CHAPTER 1

WHOLE NUMBERS

LESSON 1
Objectives:
 Give the place value of each digit in 3- to 6-digit numbers

Materials: Module, computer/phone

PLACE VALUE

Let us investigate

The third highest mountain in the world is Mt. Kanchenjunga. The height of this mountain is
8 586 meters. It can be found in the Himalayas.

How do we read 8 586?

It is read as eight thousand, five hundred eighty-six.

Each digit has its own place value.

Below is a place value chart.

Thousands Units

Hundred Ten Thousands Hundreds Ten Ones

Thousands Thousands
8 5 8 6

The place value system uses the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. The digits are grouped into
two periods, the units and the thousands.

For example, 8 is in the thousands place. To get the value of 8, multiply it by 1 000.

8 x 1 000 = 8 000 The value is 8 000.

Each digit has its own place value and value. The value of the digit is known by multiplying the digit
by its place value.

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 Try this

A. Complete the table by writing the digits to their proper columns.

Thousands/Units Hundred Ten Thousands Hundred Tens Ones

thousands thousands

1. 5 948
2. 2 891
3. 63 193
4. 422 592
5. 841 427

B. Write on the blank the place value of each underlined digit.

1. 698 794 _________________________

2. 260 005 _________________________
3. 659 914 _________________________
4. 481 991 _________________________
5. 391 866 _________________________
6. 561 901 _________________________
7. 621602 _________________________
8. 428 636 _________________________
9. 517 195 _________________________
10. 390 348 _________________________
== End of the Lesson ==
LESSON 2
Objectives:
 Recall the previous lesson
 Read and write through hundred thousands in words
 Read and write through hundred thousands in symbols

Materials: Module, computer/phone

READING AND WRITING THROUGH HUNDRED THOUSANDS

Let us investigate
Red Cross volunteers raised P789 821.00 from the “Barya Mo, Buhay Ko” program. They asked
MRT commuters to drop their excess coins in cans, which were located at the stations’ counters.

How do we read 789 821?

It is read as seven hundred eighty-nine thousand, eight

hundred twenty-one.

In reading numbers, we start from left to right digits.

Let us have other examples.

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 a. 478 204
This number is read as four hundred seventy-eight
thousand, two hundred four.
b. 78 129
It is read as seventy-eight thousand, one
hundred twenty-nine

To read numbers, start from the leftmost digit to the rightmost digit.

Try this
A. Read these numbers aloud.

1. 8 782 6. 68 120
2. 6 422 7. 58 325
3. 5 314 8. 22 257
4. 3 852 9. 694 818
5. 41 924 10. 716 809

B. Write the following numbers in standard form.

____________________ 1. Eight hundred thirty-four

____________________ 2. Seven hundred fifty-nine
____________________ 3. One thousand, sixty-five
____________________ 4. Eight thousand, seven hundred forty-seven
____________________ 5. Seven thousand, six hundred twenty-three
____________________ 6. Twenty thousand, six hundred nine
____________________ 7. Nine hundred thousand, eighty-five
____________________ 8. Thirty thousand, six hundred ninety-one
____________________ 9. Four hundred forty-eight thousand, nine hundred seventy-four
____________________ 10. Seven hundred thousand, ninety-three

C. Write the following numbers into words.

1. 3 514 ________________________________________________________________________________

_____________________________________________________________________________________

2. 8 087 ________________________________________________________________________________

_____________________________________________________________________________________

3. 3 871 ________________________________________________________________________________

_____________________________________________________________________________________

4. 62 208 _______________________________________________________________________________

_____________________________________________________________________________________

5. 880 449 _____________________________________________________________________________

_____________________________________________________________________________________

== End of the Lesson ==

FORMATIVE ASSESSMENT

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TEST I. Match column A with column B by writing the letter of the correct answer on the blank.

A B
_____ 1. 58 214 a. twenty-six thousand, one hundred forty-three
_____ 2. 75 559 b. sixty-five thousand, six-hundred eighty-five
_____ 3. 26 143 c. fifty-eight thousand, two hundred fourteen
_____ 4. 65 685 d. forty-two thousand, one hundred twenty-two
_____ 5. 42 122 e. eleven thousand, five hundred nine
f. seventy-five thousand, five hundred ninety-nine

TEST II. Write the following numbers into words.

1. 5 425 ________________________________________________________________________________
_____________________________________________________________________________________
2. 42 911 _______________________________________________________________________________
_____________________________________________________________________________________
3. 80 193 ______________________________________________________________________________
_____________________________________________________________________________________
4. 27 759 ______________________________________________________________________________
_____________________________________________________________________________________
5. 876 305 _____________________________________________________________________________
_____________________________________________________________________________________

TEST III. Answer the following:

1. The number that comes after 8 888 is __________.

2. The lowest numbers with digits 1, 3, 9 and 8 is __________.
3. The greatest number with digits 9, 1, 0 and 2 is __________.
4. Add half of 1 000 to the hundreds of 3 421. The answer is __________.

GOD BLESS!
LESSON 3
Objectives:
 Recall the previous lesson
 Express the relationship of numbers using the expressions “Less than ( < ),” “Greater than ( > ),”
and “Equal to ( = )”

Materials: Module, computer/phone

COMPARING AND ORDERING NUMBERS

Let us investigate
When Annie and Minnie received their monthly salaries, both were very excited to shop
at the mall. Annie got P4 365.00 while Minnie received P4 120.00. Who between them
could buy more?

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 By comparing the digits in the hundreds place, 3 is greater than 1. So 4 365 > 4 120.
Therefore, Annie could buy more than Minnie.

Let us have another example.

Compare 3 278 and 3 761. In the thousands place, both digits are the same. But in the
hundreds place, 2 is less than 7. Therefore, 3 278 < 3 671.

The symbol = means that the two numbers or quantities are equal.

Arrangement of Numbers

1. Ascending Order - smallest to largest number

Examples: 73 456 , 73 598 , 74 891

2. Descending Order - largest to smallest number

Examples: 98 732 , 98 621 , 95 124

Try this
A. Encircle the bigger number in each pair.

1. 9 659 3 543 6. 77 831 30 922

2. 3 117 7 078 7. 70 299 25 287
3. 2 523 2 785 8. 53 223 49 108
4. 7 998 9 113 9. 45 832 42 808
5. 7 466 3 170 10. 83 673 42 724

B. Put a smiling face on the blank if the number sentence is true and a sad face if it is false.

_____ 1. 8 434 < 2 547 _____ 6. 75 995 < 50 072

_____ 2. 4 068 > 3 650 _____ 7. 41 318 > 50 661

_____ 3. 9 613 < 3 549 _____ 8. 54 072 < 88 127

_____ 4. 8 794 > 5 814 _____ 9. 36 510 > 72 205

_____ 5. 3 527 < 9 083 _____ 10. 30 650 < 81 694

== End of the Lesson ==

LESSON 4
Objectives:
 Recall the previous lesson
 Round off numbers to the nearest tens

Materials: module, computer/phone

ROUNDING OFF NUMBERS TO THE NEAREST TENS

Let us investigate

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 The approximate number of Filipino athletes for the Olympic Games is 300. There are 20 nations
who joined the games.

The numbers 20 and 300 are round

numbers they are the numbers nearest
to the exact values.

How do we round off numbers

to the nearest tens?

Look at the number line below. If we round off 16, the number is nearer to 20 than to 10.

10 11 12 13 14 15 16 17 18 19 20

Based on the number line, 11, 12, 13, and 14 are nearer to 10 than to 20.

Study these examples.

59 60 368 370
33 30 162 160
84 80 204 200
92 90 699 700
75 80 122 120

Look at the digit at the right of the tens place. If the digit is 0, 1, 2, 3, or 4, round it down.
Replace the ones digit with 0. Then, copy the digit in the tens place.

If the digit at the right of the tens place is 5, 6, 7, 8, or 9, round it up. Replace the ones digit
with 0. Then, add 1 to the digit in the tens place.

Example:

Round off 157 to the nearest tens.

The digit of the right of 5 is 7.
Replace 7 with 0.
Then, add 1 to 5 making it 6.
Therefore:
157 160

Try this
A. Write round up or round down to round off the following numbers to the nearest tens.

____________________ 1. 78 ____________________ 6. 391

____________________ 2. 51 ____________________ 7. 224
____________________ 3. 57 ____________________ 8. 336
____________________ 4. 86 ____________________ 9. 851

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 ____________________ 5. 25 ____________________ 10. 540

B. Round off the following numbers to the nearest tens. Encircle the correct answer.

1. 26 ( 20 30 40 )
2. 82 ( 70 80 90 )
3. 63 ( 60 70 80 )
4. 49 ( 30 40 50 ) C. Write three possible numbers that
5. 40 ( 30 40 50 ) can be rounded off to:
6. 228 ( 230 210 220 ) 1. 60 _____ _____ _____
7. 876 ( 860 870 880 ) 2. 80 _____ _____ _____
8. 736 ( 720 730 740 ) 3. 100 _____ _____ _____
9. 404 ( 400 410 420 )
10. 311 ( 290 300 310 )

== End of the Lesson ==

FORMATIVE ASSESSMENT

TEST I. Compare the numbers using > , < , or =.

1. 3 011 6 025 6. 87 325 72 595

2. 8 182 4 104 7. 78 371 51 262

3. 5 670 4 575 8. 60 030 83 998

4. 7 003 6 972 9. 23 101 55 473

5. 4 036 2 974 10. 50 554 77 567

TEST II. Arrange the following numbers on the left in ascending order and on the right in descending order. Write
1-5 on the blanks.

Ascending Descending

_____ 1. 63 244 _____ 1. 62 555

_____ 2. 65 002 _____ 2. 61 998
_____ 3. 64 999 _____ 3. 63 019
_____ 4. 61 111 _____ 4. 64 333
_____ 5. 62 199 _____ 5. 65 360

TEST III. Round off the following numbers to the nearest tens.

1. 77 __________ 6. 882 __________

2. 78 __________ 7. 606 __________

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 3. 28 __________ 8. 692 __________
4. 68 __________ 9. 899 __________
5. 53 __________ 10. 589 __________

GOD BLESS!

LESSON 5
Objectives:
 Recall the previous lesson
 Round off numbers to the nearest hundreds

Materials: module, computer/phone

ROUNDING OFF NUMBERS TO THE NEAREST HUNDREDS

Let us investigate
There are 340 species of reptiles, 394 living mammals, and 263 kinds of amphibians in China.

How do we round off 340, 394, and 263 to the nearest hundreds?

When rounded off to the nearest hundreds.

340 300
394 400 how do we round off numbers to the nearest hundreds?
263 300

The first step is to look at the digit at the right of the hundreds place. If the digit at the right is less
than 5, round it down. If the digit at the right is greater than 4, round it up.

215 when rounded off to the nearest hundreds is 200

235 when rounded off to the nearest hundreds is 200
245 when rounded off to the nearest hundreds is 200
261 when rounded off to the nearest hundreds is 300
275 when rounded off to the nearest hundreds is 300

Try this
A. Encircle the number at the right of the hundreds place digit, and write round up or round down.

____________________ 1. 848 ____________________ 6. 4 848

____________________ 2. 476 ____________________ 7. 7 126

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 ____________________ 3. 491 ____________________ 8. 9 070
____________________ 4. 339 ____________________ 9. 9 028
____________________ 5. 605 ____________________ 10. 7 250

B. Round off the following numbers to the nearest hundreds. Encircle the correct numbers.

1. 746 ( 700 800 900 )

2. 803 ( 700 800 900 )
3. 287 ( 200 300 400 )
4. 818 ( 700 800 900 )
5. 569 ( 500 600 700 )
6. 3 524 ( 3 500 3 600 3 700 )
7. 3 008 ( 3 000 3 100 3 200 )
8. 7 347 ( 7 200 7 300 7 100 )
9. 7 956 ( 7 000 8 000 9 000 )
10. 2 893 ( 2 900 3 000 4 000 )

C. Write three possible numbers that can be rounded off to the following numbers.

1. 500 _______________ , _______________ , _______________

2. 700 _______________ , _______________ , _______________
3. 1 500 _______________ , _______________ , _______________

== End of the Lesson ==

LESSON 6
Objectives:
 Recall the previous lesson
 Round off numbers to the nearest thousands

Materials: module, computer/phone

ROUNDING OFF NUMBERS TO THE NEAREST THOUSANDS

Let us investigate
The Math Quiz Bee participants visited three countries for the competition- South Korea
with 98 480 square kilometer land area, Taiwan with 35 980, and Armenia with 29 800.

How do we round off 98 480, 35 980,l and 29 800 to the nearest thousands?
Nearest Thousands
98 480 98 000
35 980 36 000
29 800 30 000

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 If the digit following the thousands place is 5, 6, 7, 8, or 9, change the digits at the right
of the thousands place to 0. Then, add 1 to the digit in the thousands place.

If the digit following the thousands place is less than five, change the digits at the
right of the thousands place to 0. Then, copy the digit in the thousands place and the digits at its
left.

Study the examples below.

2 234 2 000 35 712 36 000
1 989 2 000 37 902 38 000
4 829 5 000 36 090 36 000

Try this
A. Write round up or round down.

____________________ 1. 7 922 ____________________ 6. 897 384

____________________ 2. 54 496 ____________________ 7. 7 333
____________________ 3. 3 694 ____________________ 8. 277 952
____________________ 4. 74 778 ____________________ 9. 37 772
____________________ 5. 4 698 ____________________ 10. 705 222

B. Round off the numbers at the left side to the nearest thousands. Encircle the letter of the correct
answer.

1. 4 815 a. 5 000 b. 6 000 c. 7 000

2. 9 547 a. 9 000 b. 10 000 c. 20 000
3. 2 504 a. 2 000 b. 3 000 c. 4 000
4. 55 702 a. 56 000 b. 46 000 c. 4 000
5. 32 038 a. 33 000 b. 32 100 c. 32 000
6. 35 973 a. 36 000 b. 37 000 c. 38 000
7. 802 530 a. 802 000 b. 803 000 c. 804 000
8. 632 295 a. 632 000 b. 633 000 c. 634 000
9. 311 500 a. 310 000 b. 311 000 c. 312 000
10. 715 585 a. 715 000 b. 716 000 c. 717 000

== End of the Lesson ==

FORMATIVE ASSESSMENT
TEST I. Round off the following numbers to the nearest hundreds at the left and to the nearest thousands at the
right.
Hundreds Thousands
1. 514 ____________________ 6. 1 870 ____________________
2. 921 ____________________ 7. 2 318 ____________________
3. 864 ____________________ 8. 3 570 ____________________
4. 6 319 ____________________ 9. 6 463 ____________________
5. 9 879 ____________________ 10.7 800 ____________________
TEST II. Round off the numbers at the left to the nearest hundreds. Encircle the letter of the correct answer.

1. 470 a. 400 b. 500 c. 600

2. 790 a. 600 b. 700 c. 800
3. 486 a. 400 b. 500 c. 600
4. 2 975 a. 3 000 b. 4 000 c. 5 000

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 5. 8 972 a. 8 000 b. 9 000 c. 1 000
6. 9 565 a. 9 600 b. 9 700 c. 9 800
7. 74 275 a. 74 100 b. 74 200 c. 74 300
8. 85 540 a. 85 400 b. 85 500 c. 85 600
9. 56 375 a. 56 400 b. 56 500 c. 56 700
10. 33 998 a. 32 000 b. 33 000 c. 34 000

TEST III. Write three possible numbers that can be rounded off to:

1. 5 000 ____________________, ____________________, ____________________

2. 10 000 ____________________, ____________________, ____________________

GOD BLESS!
LESSON 7
Objectives:
 Recall the previous lesson
 Identify the ordinal numbers from 1st to 100th

Materials: module, computer/phone

ORDINAL NUMBERS
Let us investigate
Ordinal Numbers are used to show the relative position of an object in a given set.

Ordinal Numbers Ordinal Number Words Ordinal Numbers Ordinal Number Words
1st First 20th Twentieth
2nd Second 21st Twenty-first
3rd Third 22nd Twenty-second
4th Fourth 23rd Twenty-third
5th Fifth 24th Twenty-fourth
6th Sixth 25th Twenty-fifth
7th Seventh 26th Twenty-sixth
8th Eighth 30th Thirtieth
9th Ninth 40th Fortieth
10th Tenth 50th Fiftieth
11th Eleventh 60th Sixtieth
12th Twelfth 70th Seventieth
13th Thirteenth 80th Eightieth
14th Fourteenth 90th Ninetieth
15th Fifteenth 100th Hundredth

Try this
A. Write the following ordinal numbers into words.

____________________ 1. 9th ____________________ 6. 16th

____________________ 2. 21st ____________________ 7. 25th
____________________ 3. 12th ____________________ 8. 1st
____________________ 4. 5th ____________________ 9. 23rd
____________________ 5. 15th ____________________ 10. 8th

B. Find the message of the numbers below using the letters of the English Alphabet.

11
 _____ _____ _____ _____ _____ _____ _____ _____ _____
11 14 15 23 12 5 4 7 5

_____ _____
9 19

_____ _____ _____ _____ _____

16 15 23 5 18

== End of the Lesson ==

LESSON 8
Objectives:
 Recall the previous lesson
 Read and write Roman Numerals

Materials: module, computer/phone

ROMAN NUMERALS

Let us investigate
Lito was asked to visit his friend in the hospital. His friend is in room 17. When Lito arrived,
He looked for the room and saw this sign on the door: XVII. Help him find the room.

XVII XVIII

Number 17 is in Hindu-Arabic numeral. In Roman Numeral, it is written as XVII. Both numbers are
equal.

We can express numbers from Hindu-Arabic to Roman Numerals and vice versa.

Study the chart below.

Roman Numerals Hindu-Arabic Numerals Roman Numerals Hindu-Arabic Numerals
I 1 C 100
V 5 D 500
X 10 M 1 000
L 50

Roman Numerals I, X, C, and M can be repeated three times. When a Roman Numeral with
smaller value comes before a Roman Numeral with bigger value, we subtract them.

Example: CM = 1 000 – 100 = 900

When a Roman Numeral with smaller value comes after a Roman Numeral with bigger value,
we add them.

Example: MC = 1 000 + 100 = 1 100

A horizontal bar placed above a Roman Numeral is called vinculum. It means times 1 000.
_

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 Example: V = 5 x 1 000 = 5 000

Try this
A. Write the following numerals into Roman Numerals in expanded form. Then, combine them to have
a single Roman Numeral.

1. 36 = __________ + __________ = __________

2. 48 = __________ + __________ = __________

3. 42 = __________ + __________ = __________

4. 25 = __________ + __________ = __________

5. 99 = __________ + __________ = __________

== End of the Lesson ==

FORMATIVE ASSESSMENT
TEST I. Match column A to B. write the letter of your choice on the blank.

A B
_____ 1. 60th a. ninetieth
_____ 2. 22nd b. fiftieth
_____ 3. 90th c. sixtieth
_____ 4. 3rd d. twenty-second
_____ 5. 15th e. third

TEST II. Write the following Roman Numerals into Hindu-Arabic numerals.

__________ 1. DCIII __________ 6. MMCXCVIII

__________ 2. CCCLIV __________ 7. CCCLXXXIX
__________ 3. MCCLIX __________ 8. MCMXCV
__________ 4. CDLXXVIII __________ 9. DLXXIII
__________ 5. DCCXLIV __________ 10. CCCXL

TEST III. Match column A with column B by writing the letter of the correct answer on the blank.

A B
_____ 1. 86 a. XXXV
_____ 2. 74 b. DCXXXII
_____ 3. 64 c. VDXIV
_____ 4. 35 d. IVDCCLXXXVII
_____ 5. 963 e. LXXXVI
_____ 6. 632 f. VICDLXXXIX
_____ 7. 943 g. LXIV
_____ 8. 5 514 h. CMXLIII
_____ 9. 4 787 i. IVCDLXXXIX
_____ 10. 6 489 j. CMLXIII
k. LXXIV

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 GOD BLESS!
LESSON 9
Objectives:
 Recall the previous lesson
 Differentiate the different properties of addition

Materials: module, computer/phone

PROPERTIES OF ADDITION

Let us investigate
The candidate for Ms. Green Peace garnered 5 stars from the NCR voters and 3 stars from
the Visayas region.

What is the total number of stars she got?

Are 5 and 3 equal to 8?

Are 3 and 5 equal to 8?

What if you group 8 stars into 3, such as: (2 + 3) + 3 or 2 + (3 + 3)

Is their sum still 8?

This shows the Property of Addition.

1. Communicative Property
 Changing the order of the addends does not change the sum.
Example:
2 123 + 7 893 = 7 893 + 2 123
10 016 = 10 016
2. Associative Property
 Changing the groupings of the addends does not change the sum.
Example:
200 + (300 + 400) = (200 + 300) + 400
200 + 700 = 500 + 400
900 = 900

3. Identity or Zero Property

 Any number when added to Zero, the sum is the number itself.
Example:
980 + 0 = 980 or 0 + 980 = 980

Try this
A. Identify the property of addition shown in each equation.

____________________ 1. 0 + 751 = 751

____________________ 2. 252 + 685 = 685 + 252

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____________________ 3. (51 + 97) + 91 = 51 + (97 + 91)
____________________ 4. 0 + 485 = 485
____________________ 5. 881 + 824 = 824 + 881
____________________ 6. (91 + 28) + 51 = (91 + 28) + 51
____________________ 7. 0 + 461 = 461
____________________ 8. 894 + 327 = 327 + 894
____________________ 9. (88 + 67) + 65 = 88 + (67 + 65)
____________________ 10. 0 + 473 = 473

B. Write the missing numbers. Then, identify the property of addition used.

____________________ 1. _____ + 197 = 197

____________________ 2. 825 + _____ = 535 + 825
____________________ 3. (44 + 69) + _____ = 44 + (69 + 28)
____________________ 4. 0 + _____ = 927
____________________ 5. 854 + 345 = _____ + 854

== End of the Lesson ==

LESSON 10
Objectives:
 Recall the previous lesson
 Add 3- to 4- digit numbers without regrouping

Materials: module, computer/phone

ADDITION OF 3- TO 4- DIGIT NUMBERS WITHOUT REGROUPING

Let us investigate
The farmer harvested 1 853 sacks of palay in the first quarter of the year. In the second quarter,
another 2 134 sacks of palay were harvested. How many sacks of palay did the farmer harvest in all?

What is asked?
-the total number of sacks of palay
harvested

To find the answer, use addition. Addition is

the process of getting the sum.

Start by adding the digits in ones place: 3 + 4 = 7.

Then, add the digits in the tens place: 5 + 3 = 8. Next,
add the digits in the hundreds place: 8 + 1 = 9. Lastly,
add the digits in the thousands place: 1 + 2 = 3.

1 853 1 853 1 853 1 853

+ 2 134 + 2 134 + 2 134 + 2 134
7 87 987 3 987

Therefore, the farmer harvested 3 987 sacks of palay.

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Study this another example.

Study this another example.

7 324 7 324 7 324 7 324

+ 1 465 + 1 465 + 1 465 + 1 465
9 89 789 8 789

Try this
A. Add the following:

1. 640 2. 527 3. 253 4. 4 097 5. 1 130

+ 130 + 321 + 515 + 3 801 + 5 559

B. Arrange the numbers in column and find the sum. Consume the space provided.

1. 214 + 313 2. 532 + 354 3. 363 + 630

4. 2 110 + 6 583 5. 4 153 + 4 645

== End of the Lesson ==

FORMATIVE ASSESSMENT
TEST I. Apply the commutative property of addition. Then, find the sum.

1. 718 + 925 = ______________________________ = __________

2. 822 + 420 = ______________________________ = __________
3. 524 + 260 = ______________________________ = __________
4. 791 + 398 = ______________________________ = __________
5. 308 + 556 = ______________________________ = __________

TEST II. Apply the associative property of addition. Then, find the sum.

1. 985 + (568 + 690) = ______________________________ = __________

2. (660 + 454) + 604 = ______________________________ = __________
3. (912 + 584) + 917 = ______________________________ = __________
4. 851 + (257 + 245) = ______________________________ = __________
5. 997 + (954 + 316) = ______________________________ = __________

TEST III. Write the sum in the box.

1. 3 813 6. 3 213
+ 4 032 + 1 360

2. 1 643 7. 3 084
+ 1 120 + 5 514

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 3. 1 004 8. 6 523
+ 1 990 + 2 251

4. 5 412 9. 3 165
+ 4 484 + 2 721

5. 2 610 10. 3 592

+ 1 255 + 4 106

GOD BLESS!
LESSON 11
Objectives:
 Recall the previous lesson
 Add numbers with 3 or more digits with regrouping

Materials: module, computer/phone

ADDITION OF NUMBERS WITH 3 OR MORE DIGITS WITH REGROUPING

Let us investigate
Every year, the number of OFWs increases. In 2009 and 2010, there were 3 496 and 5 827
Filipinos who worked abroad, respectively. What is the total number of workers in the said years?

To know the answer, add the given numbers. We can use the expanded form and the short method.

Using the expanded form:

3 496 = 3 000 + 400 + 90 + 6
+ 5 827 = 5 000 + 800 + 20 + 7
= 8 000 + 1 200 + 110 + 13
= (8 000 ) + (1 000 + 200) + (100 + 10) + (10 + 3)
= (8 000 + 1 000) + (200 + 100) + (10 + 10) + 3
= 9 000 + 300 + 20 + 3
= 9 323
Using the short method:
1 11 1 1 1 1 1 1
3 496 3 496 3 496 3 496
+ 5 827 + 5 827 + 5 827 + 5 827
3 23 323 9 323

17
 Try this
A. Find the sum of the following numbers using the expanded form.

1. 2 021 = __________ + __________ + __________ + __________

+ 7 855 = __________ + __________ + __________ + __________
= __________ + __________ + __________ + __________
= ____________________

2. 4 092 = __________ + __________ + __________ + __________

+ 1 156 = __________ + __________ + __________ + __________
= __________ + __________ + __________ + __________
= ____________________

3. 7 104 = __________ + __________ + __________ + __________

+ 5 365 = __________ + __________ + __________ + __________
= __________ + __________ + __________ + __________
= ____________________

4. 9 870 = __________ + __________ + __________ + __________

+ 9 597 = __________ + __________ + __________ + __________
+ 9 597 = __________ + __________ + __________ + __________
= __________ + __________ + __________ + __________
= ____________________

5. 7 621 = __________ + __________ + __________ + __________

+ 8 419 = __________ + __________ + __________ + __________
= __________ + __________ + __________ + __________
= ____________________

B. Write in the box the missing numbers.

1. 2 5 2 2 3. 1 8 5 4 5. 6 2 6 5
+ 4 4 1 1 + 3 3 2 3 + 1 3 1 4
6 3 3 5 7 7 7

2. 6 3 5 5 4. 2 4 5 6
+ 3 4 2 2 + 4 3 1 3
9 7 6

== End of the Lesson ==

LESSON 12
Objectives:
 Recall the previous lesson
 Round numbers and estimate their sum

Materials: module, computer/phone

ESTIMATING THE SUM OF 3- TO 5- DIGIT NUMBERS

Let us investigate
Last year in Fatima University, there were 236 medical students, 368 nursing students, and
511 physical therapy students. What was the total number of students enrolled last year?

18
 For quick sum, round off the addends to their greatest place value. Add the rounded numbers.

Examples:
236 - 200
368 - 400
+ 511 - + 500
exact sum 1 115 - 1 100 estimated sum

so the estimated number of students is 1 100.

7 890 - 8 000
+ 5 782 - + 6 000
exact sum 13 672 - 14 000 estimated sum
Try this
A. Round off the following numbers to their greatest place value. Then get the sum.

1. 320 - __________ 6. 17 418 - __________

+ 753 - __________ + 74 840 - __________

2. 2 626 - __________ 7. 27 672 - __________

+ 7 170 - __________ + 72 895 - __________

3. 6 107 - __________ 8. 46 316 - __________

+ 2 551 - __________ + 42 067 - __________

4. 5 751 - __________ 9. 53 141 - __________

+ 8 144 - __________ + 35 709 - __________

5. 8 514 - __________ 10. 31 902 - __________

+ 9 184 - __________ + 63 026 - __________

B. Fill in the blanks and boxes with the correct answers.

1. 835 - 800 4. 29 940 - 30 000

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 + 256 - ________ + 31 968 - 30 000
1 100

2. 9 124 - 9 000 5. 42 860 - 40 000

+ 2 998 - ________ + 45 902 - __________
12 000

3. 6 810 - ________
+ 4 568 - __5 000__
12 000

== End of the Lesson ==

FORMATIVE ASSESSMENT
TEST I. Find the sum.

1. 7 365 3. 5 540 5. 7 320

3 667 1 663 4 936
+ 1 545 + 1 935 + 4 338

2. 1 759 4. 7 042
7 821 2 206
+ 8 925 + 6 523

TEST II. Write in the box the estimated sum.

1. 653 4. 5 198 7. 655 10. 5 745

+ 815 + 743 + 546 + 7 687

2. 341 5. 3 607 8. 73
+ 690 + 4 362 + 28

3. 319 6. 246 9. 1 305

+ 773 + 350 + 610

GOD BLESS!
LESSON 13
Objectives:
 Recall the previous lesson
 Add 1- to 3- digit numbers mentally

Materials: module, computer/phone

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 MENTAL ADDITION

Let us investigate
Vincent gathered 23 old newspapers on Monday. He gathered 65 old newspapers the
Following day. What is the total number of the old number of the old newspapers he gathered?

To answer the problem, the equation is: 23 + 65 = N

Through estimation: 20 + 70 = 90

You can solve the problem by adding mentally:

20 + 60 + 3 + 5 = 88

Add these mentally.

1. 33 + 45 = N 2. 432 + 554 = N

33 - 30 + 3 432 - 400 + 30 + 2
+ 45 - 40 + 5 + 554 - 500 + 50 + 4
70 + 8 900 + 80 + 6
= 78 = 986
Try this
A. Add the following numbers mentally.

1. 6 + 9 = __________ 6. 17 + 1 = __________
2. 9 + 3 = __________ 7. 15 + 8 = __________
3. 7 + 5 = __________ 8. 13 + 2 = __________
4. 3 + 6 = __________ 9. 17 + 4 = __________
5. 7 + 7 = __________ 10. 15 + 6 = __________

B. Check (/) the box of pairs of numbers that will give the sum of 100.

1. 63 + 37 6. 44 + 66
2. 85 + 25 7. 19 + 81
3. 54 + 46 8. 28 + 82
4. 77 + 33 9. 69 + 31
5. 6 + 94 10. 5 + 95

== End of the Lesson ==

LESSON 14
Objectives:
 Recall the previous lesson
 Solve one-step word problems involving addition of the whole numbers

Materials: module, computer/phone

SOLVING WORD PROBLEMS INVOLVING ADDITION

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 Let us investigate
In a fast food restaurant, Anna bought a combo meal for P345.00 and a kiddie meal worth
P135.00. how much did she spent in all?

To solve the problem, follow these steps:

1. What is asked?
The total amount of money Anna spent
2. What are the given?
P345.00 for the combo meal
P135.00 for the kiddie meal
3. What is the number sentence?
P345.00 + P135.00 = N
4. What is the solution? P 345.00 5. What is the final answer?
P 135.00 P480.00 is the total amount of money Anna spent.
P 480.00
Try this
A. Solve the following problems by showing the steps.

1. Willy earned P13 678.00 in one month, and P14 345.00 the following month. How much are his total
earnings in two months?

a. What is asked? ____________________________________________________________

b. What are the given? ____________________________________________________________
____________________________________________________________
c. What is the number sentence? ____________________________________________________
d. What is the solution? ____________________________________________________________
e. What is the final answer? _________________________________________________________

2. Joey is a thrifty person. Last month, he deposited a total of P56 789.00 in his bank account. Yesterday,
he deposited an amount of P24 483.00. How much now is his savings?

a. What is asked? ____________________________________________________________

b. What are the given? ____________________________________________________________
____________________________________________________________
c. What is the number sentence? ____________________________________________________
d. What is the solution? ____________________________________________________________
e. What is the final answer? _________________________________________________________

3. Many has total assets of P891 342.00 after his last fight in Las Vegas, he earned another P900 000.00.
How much now is his total assets?

a. What is asked? ____________________________________________________________

b. What are the given? ____________________________________________________________
____________________________________________________________
c. What is the number sentence? ____________________________________________________
d. What is the solution? ____________________________________________________________
e. What is the final answer? _________________________________________________________

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 == End of the Lesson ==
FORMATIVE ASSESSMENT

TEST I. Add the following numbers mentally.

1. 79 4. 80 7. 33 10. 51
+ 81 + 63 + 46 + 59

2. 47 5. 33 8. 63
+ 76 + 99 + 93

3. 33 6. 76 9. 92
+ 95 + 84 + 54
TEST II. Read and solve the problems. Apply the steps.

1. Marikit sold 1 389 tickets for the first day of concert and 1 712 for the second day. What was the total
number of tickets sold?

2. Two friends went on a vacation in Aurora province. Paul drove 1 931 kilometers, while John drove 2 832
kilometers. How far did the two friends travel?

GOD BLESS!

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