VISIBLE
THINKING
in Mathematics 3APe Ue Se ne ea one ee Reo ee
eens ee ett
‘¢ Thinking Platform provides an avenue for reflection on the reasoning behind concepts and skills
Sr nOmn a nek eee eee
to the answers through detailed solutions.
it opportunities for parents and teachers to clarify misconceptions, simplify a concept or
Pes
© Parallel questions highlight differences between similar problems and allow the child to focus on
the correct application of concepts and skills.
(@) There were 15 more pupils in Class 3A than in Class 38. 20 pupils from Class 3A moved to
Class 38. How many more pupils were there in Class 3B than Class 3A in the end?
(Answer: 20 - 15 = 5; 20 + 5 = 25 pupils)
(b) There were 15 more pupils in Class 3A than in Class 38. 20 pupils from Class 38 moved to
Class 3A. How many more pupils were there in Class 3A than Class 38 in the end?
(Answer: 20 + 15 + 20 = 55 pupils)
About the Authors
“Ammiel Wan is 9 familiar name among teachers and parents in Singapore.
He has spearheaded a team in redesigning the thinking cuticlum with the
belief that ‘Every child can think’. Amiel has presented at international
conferences, including the “International Conference on Thinking’ where
his paper on “Thinking through the Conceptual Approach’ was selected for
publication in an intemational journal. He has received accolades such as
the ‘ellow of Teachers’ Network’ and has been featured in local papers fr
his innovative approach in teaching mathematics. Being a strong advocate
of teaching and continuous learning, he conducts regular workshops for
teachers, parents and pupils in Singapore
Tham Xingli holds an honours degree in Mechanical Engineering from
Nanyang Technological University (NTU) and a Post Graduate Diploma
in Education from the National Institute of Education (NIE). Through her
dedicated teaching career, she has gained extensive experience in crafting
student and teacher resource materials. She is also actively involved in
sharing sessions on teaching methodologies and in conducting workshops
for parents to guide their children to succeed academically
About Marshall Cavens
h
Marshall Cavendish Education is the leading educational publisher in Singapore,
with more than 40 years of experience in developing high-quality content
that plays a citical role in raising the standard of learning, Our publications
ate used by teachers, parents and pupil in more than 45 countries around ISaN o75281.01 15227
a | |
Marshall Cavendish sHravatolriszer!
Education[see
_ VISIBLE
THINKING
in Mathematics 3 A
‘Ammiel wan
Tham Xgl
TriceForeword
he ft the sa Vine Thinking in Mathomatir is cnn
vith te Thing Sco, Lnaing Neti? hioorly oped by Ge
iste Eaton Seappr Th ef nathan deg ord
‘pring th habit Bok cannot nove oon. ded
reson cher ho hall renner ono pegera
‘Shatter,
‘ara on xa plato oh ho hk and lt hk
‘doa faking Ov othr weg cate contre io rode
the pronase nub fnch ech fogs te pose
Frowdng nh on are cial ne degre el gcd king
fie oad
‘Aare Coan tn, act on chp drome
fd oe Tikng in Mothanats prs cca wih goa ring
frittata Leving ences ul ng ot har,
Fete tt cont rgeret ith ering mtn th ating ge
pads nae os peel ng,
exp Bon PR.
Pipa
‘anal Comes iePreface
he Visible Thinking in Mathematics: elm ci ond
eae, inkag i meena: Rt dened to flp rake Wing
Se" by potdrg” te Sod th opptuniin to Wik, ee
Cente.
“We proc hho ter prema practie wth conse ord
‘Sretel ecesloning pts he ld om rng rly ood
(Gots nn en ard tearing pect nd oad by
ease caption:
‘Thinking routines: actzndl amos to drat the i hig oo ky
‘rcpt eh aig
Parallel questions: comet ethanol rene wih he se
‘ob ilo ln word to hah gers ton peters
‘Sern od cil rds encom od beta,
‘Ws pouch ra oly in th cl ona eb ao
Ini ducpon in iktg geste mthaon
ana got sped to he chide Nate Nees pont
porate poet ard ths to de mccoy, Sy
SEEN ci doo os of ae fore
Contents
CChopter
NumbersTo 10000
umber Nlotaten And ce Vales
Reoding A Vining Numbers
CCompoing And Oreng Numba
womber Paes
Cchopter 2
‘Addition And Subtraction Wthin 10 000
[Aion Vth Regrouping
‘Addon vith Regrouig
Subrocton Wout Regreuping
Subrocton With groupe
Chapter 3
Word Problems Involving
Addition And Subtraction
Word Probes
‘More Word robles
"More We Problems (2)
Chapter 4
‘Multiplication And Division By 6, 7,
"Mdpeaton Ad Oson By &
‘lplation Ae Dion By 7
"Mstpleaton Ans Disien By 8
alpen An Ovison By 9
More Muplcobon Bod Dison By 6,7, 8 nd 9
a
2%
2
2
a
3
2
%
Fy
3
a
si
“0
a
”
n
a
aChapter 5
‘Multiplication And Division
Mutipleoon vneureprueng|
‘Mutpleaion Yi Regrowsig
Dhison thot Reprvping
‘ison Mh Regrovpng
‘ora Probie ving Four
(Operations Usa Models
‘unr Petters Imng Gaps nd Tels
Chapter 6
Mental Calculations
Addin Of2-igt Nambers
Siowodton 012-01 Nuribos
‘Mert Mutplzaton
Mest Dson|
Answers
gees
ue
cs
19
18
135
1»
ro
1 Numbers To 10 000
Number Notation And Place Value __hiakinig Paton
patna 109
“Think Tethis conser wy?
0999,
‘hissondsioe —thestonds for histondefor
‘undece| Stans ones
1900, om, ‘8.
199999,
ees 7
C — |
Gasser desea ye ievee temas
‘Stouonds Shunde Stans Sones
5000, 7900, or90 orve dn Hc Ot —
=
eee ee ee
a ve er i
|
be De Ls Ge "
ve tn ri el cae a
ee em | cl Gas = Os
Tet, | Thousands | Hundreds: ‘Ones: J
a
a
7 tn fe SaaS wo
eae 2 wD
SAPS, serationmantotedt
(ayers =
au ‘Thousands | Hundreds | Tens ‘Ones: +)
Go)
of? [s (oo)
Think con you Ken he mista? hy do you tink she mad he mistake?
con youwie 248in cher wast
1248 con be writen os 248 cnos
or 128 ona Bones
‘er Izhundrods@ ers 8 ones
12 heels 48 oes.
ec mecer
{Fic
os o
abo eba
3)2. Flin tebionks 4. Aine blanks,
‘Example exemple
167964, thedgt_4_isinthetens place ond 2000 cn be represented os.
‘the dt sas te valve ot 900
(©) 13867, the digt____sinthoones place and
‘ne dg ss te vole of
(2) 15082, the dig _IsinthePundeds place and (ese on eaten ms ————_ Seas
‘he dg 8 hos thevabe of bonnets
{c1119609, the dg ____Isinthehousonds plac on “ nuncio
the gt 6 host veo. * =
3. Flin hobionks . =
Jo) 8 thowsnds « —_tens (2) 0 con be epreseniedos __ thousands
1 6 thoesnds uncecs ones
le ahundees: tone Gs hundreds
4) 390 ens = __huneds ones
le) Ther are —__ ens in 1200, o tens
1 There re rund 7300. ones
|g) Tere re __rousons in 600. ut ni
1 Thereore. ‘peusoas in 00,
8 mneeptnenenst nent net er erm cd pe emer 8
ad| 5. Fllintheblonks Clos ut (the wrong answers
Example —txemple
[setts ams Eaanisepuonas |
| -—s00 ‘ (Games > 7s > | |
5006
| ee 2ihowsonds hundreds 6 ere Tone |)
(tia os
(a) SB lens + 60005 =
(a) $203 canboopressod
sthousands 208 tens 5203 ones
ase eee ae { Sadana seme
eee ee [aan | [anmaaaon |
[b) 9170.con bo expressed os:
* @thundreds 70.0nes ff meets 7
[Ean
so =d
6 tempers cameo ate igen tne attend vera 7
1) Shunde + 4tons7, Reastne cues. Use the dts below to frm:
Then cre the cored mumbw
Example
| (4 theses pose nbn
iar | COCO
eaneatet
I | © 9 O®
2501 on
Ja) Thawed! Sintheones pce
Eom oteter ho 01s lo the sms! posse rumba,
{hecgen the ons paces uc he dg inthe hundreds pace OOO®
695 65 26s e589
Ib the rote poste number
"Enos nosound @ © © © a
Taragho hes fess meshed te
nares pce. |e the smaest pose umber betweon 2500 on 4000.
wt O©OOO ——
(2 thowaggt cheng 1 ges putin S759
Toryaatantaneaia
Teueitee trio nowtonts dite 3
meant OOOO
re J ogee xt rman no
OOC® —| Reading And Writing Numbers ___tikinsiPatse, = — satis
Josephs bing a compute 1. Wein numbers
lo) two thousand end thinesn {2013
(a) two shoueond nd they —___[~ 203
(2 Four thousnd, nee hundred and Went-one
(2) Fourthousand, wo hunted ond ton
(6 Theo thousand, re hundredandferton
(@ Thee thousand, ehundredand ony
{e} Four tousand, seven hundred ndone—{
(Four housand, sven handed nd ten
UU
JU
Think! Olde cut he cheque conechy? Wy? (gl Seon hewn ero
47
|
1H Soren heusand ond ninly
| serous. atc n vr omh Ung eunpe teenie
Ages iadicenewenmearchwss ncevosoneay Shiwownrrrenh Nine thousand and fy-rine
‘Rayaane owes hare word dn nate we ern at were
etal te Garena aianaenomonaeacntescanart 1D Nine thousand, fe hundred and nine
UU
10 anna cmtmaumanemanativentne thd manne migra!
|
2. Cela te mists
ib son
Example
im = m0
eee syne sto)
tl 692 -sxhaond hres hunced odin | aan
wy 03 st Rowson ond four hunted oe
© 70% seven housed, wo hunted and sn |
a ene ‘ahha leven and si
(4 6590
te 508 fad tree hun od ot
409
2. Wen numbar wets ae
(Example
‘oo ene thowsond and nine 708
1o0 —_enethtsondondinete 80
a er thasond and nie hundred 705
x3
a mean | ee
woe as
my
es
i‘Comparing And Ordering Numbers __‘thiskia tis: ee
‘Wayne wos ostd fo compare o numbars ond ccs gree ruber, 1. Sempare ond one has nob.
He wos dls requredo eon fis chokes
(a) Jes, Poe Soen ond owe each have sae money.
Lookat he questions andhis ane, | ret area rey hve, Sen ah eect
‘omaintlmony|
‘ueston
Ga (seas [Paar Siren [dena )
(nie [sane [sis aavs)
Both numbers are the sone because the siits 7,8 and 9
are nthe some place wales.
1) ony coe, ee an ick eoch sol some books.
‘Order the numb of books ey hove sod begining with he
veton 2 (eats! numba ol boks
oo a
ie
vee)
3420
‘15 ie greater than 6481 because the last digit in 3415
\soreater than the lst cgi 6451 a
_ 3204
3082
sa)
(2 Wary, tne, monde on ery uses diferent araunts of up
ink Di Wopeuse hese neta conpr he unbes ‘oars br fe a
inbangusant Gran amount uel bp wh te sole
‘yeu Eiko xd Woy cone? crore
iver wh nt
(Cana [ery >)
(Gaoseme [3408 | 4308 mi | 3048 mi)
§ Seem meitt —
fomnecsteree osi fs Sond, yo, Balle andro were kiting sects
‘defo ember sites hey hove done, bepiing vt the
‘sales number of sees
(seria [Tye [ ete [ee
(Coes [ seas [ see [sae]
nae
2. arrange te follng numbers. Begin wh the greats.
os fe0) Ste) (ees), 4 (8)
mn
wo ie Ga Gas Sais so
vt
5 Aronge the follwing numbers. Bog wh fo smal!
ame) a8
oy Some “ae \zte oar
Ye warts msersenwthnnritenpamine
example
®O2OO®
Use hee igs orm
(ol the recast Aig rrr,
(01 the smales ¢-dgt cure.
“OO@Q®
Use hese ago farm
(ol the retest rumer.
(0) Sesmales' gt numer
“OOOO
Use thse dso form
(o) tho grote 4g curr.
(8) the smolst 4-igt eur
“OOOO
Uso se dito form
(@) the grote! ig curter
ben 6800 ond 8600,
1) fhe smatest 4d mune
bowen 6800 and 3600
cd or i etree 17Number Patterns a
There or nay pes of number pate
‘het nuber potems inal edd or subtracing the sare number each iene
so sme 0
o 2m
1, a, mie
wk ee
wh SCO.
‘he ptiens below ive a ctr the nurs aed or state,
6 cm
wk RE BK As
ee ee
so BCC
con you compl these numbor poems?
ft 10,200, so, oe
te 100, 200, —__. ____.
(a ____. 200, ____. 00,
(a) og, 0
Think How many numiberséo you nod to ety umber pane? Why?
Compas ech mer paren
Example —
(ol 7088, 7059, 7070 7071 72.7078
(b) 2087 706,707, 7089 7099,__7108
(a 7099, 71627269, 7069, 75697569
1 1908,
by 1943,
(e783, 1983 2583,
2 4650, 4650,________470
» 4030, aago, ___ 4490
onsen soon sen
3. fo) 9017, 5015, __.____ 9009,
) ____ soa, 9025, 022, __ 9016
(905, 9015, _.__. ava
fd eee ee 4905
(by 5905, __s2gs,_saas,
5005, 5255, S205Addition And Subtraction
2 Within 10 000
Addition Without Regrouping _ iiss.
Seven ode some numbers Here te hs soins
Flin he bors.
@ aene * ware
Thinkt Can you spothis mstckas?
We the caret elon in he box eloi
|) steven no gn he gts bose on hs place wales ore ond
{et ve ke hon the mara re added below I
ee,
to) 23492
inthe ramber 12 the ig isin te fons place and the dt 2 sn
the oes ple,
Fest odd the ones.
‘ones ones 6 ones
Nest, od ts
i Bienes Ten = ens
Then he hunceds,
huncreds » Dhunsreds = 2 hundeds pons
1 1039 +42. 2 swseai
lost, athe thousonds. 45074301
ousond +0 meueands «thousand
| 0,124 12 1246,
(oy 1234 +123
“ho mumber 123, he itis in fhe hundreds poche dg 2s the
fence ond the digs inte ones pace
5. 586+173 - 6 200+ 3201 =
Frat ad the ons. mare
Ne odd he ens. + 123
| Shere + 2 = 5 tons css
|
Thane the hued
hundreds hunted =3 hundeds
{sty oth heusonds
‘ilsond + 0 usonds = housand 7 $0064.n52~ 8, 167 +2.
50,204 + 120 = B57
matte
ACSI ama tsarnbes ih toe pes eect bt anes
DasapealeTaayetseae None atnape tenAddition With Regrouping ____ "siete,
Stevo added some numbers Hoe are his sluions.
"eee ei
‘Think? Con you pois makes?
temas
~—s
a
et concern box aw
=
24 netangrnte rare en os
Soren dd not regroup fra) and
Totus lok tow te numbers ae ede below
fo weeser
fs of for
jouer sere
ser ot te oe are)
flere ae soa!
cred one
‘hen, he hanced.
hundreds +S hundreds + huaded = 8 hundreds
st, the thousands.
‘howeand + hovsonds = cusond
0,123 +567» 180,
vee sora
fst odd he ones
2inndteds¥ hundreds + Thuaded = 9 hundreds
{sty the housands
"ousand ss thovsonde= 6 fhwvsonde
50,1234 + 5676 = 6912
tes
Seehenmcnpnsennannepg os nay ne ale ngoons___Attning Mastery
6
fe
|
a,
1 325 +68 = A
sans
* os
3. 10264595 = 4. 2859.78
5. 3564 +8962 6, 9506+ 3687 =
7, 494642049 = 8, 670942953 «
cme en tigen soe mngrinnans 7Subtraction Without Regrouping __ Tiki meus,
Cae EMS
ia
Think 00 these sonencs mean ho sare hing? Would you obin he sare
‘nso or bth qustons? xan
Stoven svbroced some numbers. Here aes solitons,
pare woe
a4
Thinket Can you spots mstokes? Cre hom.
te const seins inthe box eo
ant eed nantes 28Stove dd not ogn he digs sed on ss pte volves fr oth oar
[eros lok ot how te umber ar subrocied below.
(1 34-1 ance
Inns rnbee 2 ho dig is inthe fens place on ig 218 9
‘hecnes place
1 1869-427
it nico
rere ®
ot ntte ttre .
oS :
ane ea
Hare ered
aaa
ee aa
aire
ale se
|
(oy 34-123
Tithe number 123 he gt is the hunted place, he dat 2 sin
the one xe ond he igh 3m te ones pace,
5. 5862-2021
Frat sub he nes a
ones Sones = Tone .
‘No subtctthe ons 2
‘ene 2tens= fen 3
“hen subroe thhundds
Zhuncrede = hundred = hunted
Last, soc he thousands
Thousond~housandr = housond
0.129428 =1m,
20
1 oe
rs
7. e9a4-1510
6 estore earnest
Q SeStresematrccmnsenes
20 weemteprarnns ean memcmaemnanttnpenitiarei Peeiscaounta eerie
4, 4990-113
6, 6908 ans
8. 780-6020 =‘Subtraction With Regrouping —_
Stove subholed some rumba Here ores sions
oO mane % gare
(as = ad
‘Think! Con you spot hs meskes?
([cecetoraan
Wit th coret soon nthe box bow
Steven det rt rgtoup fo bot (ond
{err lok thaw the numbers ere subtracted bow
(al 136-67
Fit subtot me nes.
"ones cane! besubracted fon 4 ones.
Rogtup the ons ond ons.
Sane ones = tans ones
subaat
‘ones -7 ones =7 ones
Ne subd the tens
(tens contr be surat om 2 tens.
ogre he hundreds on ins
‘hundreds 2 ene = Vhunde iene
Subhoe.
Tens tons = 6 tons
Thon sublet ho hundieds
ThondedOhundeds= 1 honed
Lost, sbi he thovsonds.
"hetsond =O housonds =
reson
So 1234-67 = 67,
°
y
Saree(236-367
sist uate oes wane
ene cael be Subtoce om 4 ones. mini
Ragrup he ens ond ones.
Stare anes = fons Maes
ssuoe.
‘ones -7 ones =7 ones
1. m3 -st42__ 2, 365 =
Noa sutra the rs
(ene conna be surat rom 2 fens.
Rogrup hehundredsonc tens.
‘hundreds? ens = Tranied 2 ens
subroe.
Tens = 6s = 6 ns
8, 2392-1665 =, 4.122867 =
‘Then sbi he handed
‘hundreds comet be sueded om hunced
Fegroup he housonds ond hued
Thowsond hundred = DIheusonds i hundeds
Last, src the hands. 5, 02-698 = —_ 6, sm0- 1689
hundreds — 3 handeds =
hundreds
0, 204-367 = 867
7, 2400- 636~. 8, 9009-4724 =
§ PEE econ rennet
ae‘Sole, Show your work
9, Wats 87 ss thon 360?
10, Whats 18 ess han $050?
11, The sum of wo numbers 4853, One ofthe nubs 699.
‘ils the ater rumbe?
12. Thesum of wo nmbetse 8200, One ofthe numbers is 705,
‘Watis the oer umber
18, The teres botasan to numbers 183, The grote numbers 4055,
Vitis to salir number?
14. The ifrence beeen wo rumbets i 2682
‘The greater number 7000, Whats the ser number?
36 eetaitnet enum creahveeegnemnaent
15, dor utr emis numbers
Examplere) cise ke ty ah win wean
i Word Problems Involving
6 3 Addition And Subtraction
Word Problems __
Lek at hese roles,
Thinking Plt
Problem
Fis Oar mae 250 fos nthe maming. She made another 45 as nthe
‘fernoon How man ors ol se make agatha?
Problem 2
Firs won nde 250s nhemarrng. She made 1&5 more ors
(erneon How many los ddshernckeatogether?
Problem 3
Fes van mode 250 asinine morning She rade 145 fever ersin the
(emoon, ow many tots dsho make cogoter?
‘Think. How tthe pobis snr? How are they deren? Cee the key
Ti yor hot make ham deren om ene note:
(Con you use the seme model soe theo problems?
ak
SC Game
2 Gen
i ere ee ahnansietomeraiytesien annie Son re
0 enero anne ee ne
‘row modes ond sabe these prions.
Example
Doritos 524 mares. Henry hss 298 mais. How many marbles
thoy how allogethe?
toyed
5244296822
Tey hove 822 marbles atogetor,
1. Doriahos 524 mats He hos 98 more marbles han Henry How many
mats des Hey hove?
%@
2. ane has 524 mats He hos 298 fear eras han Here. How ma
rable does Her hove? ™3. Kimberly sl 597 fcktstor concer Sove sold 216 kas Hou mary (6. A posimon dvered 02 erson Monday He dtvres 245 eters on
feels i both of ram al aogether? “Tuestoy How mony lies ce deer on bot day?
44 eben sold 597 cessor a cnca. Stoe sold 2¥6 moc ks han 7. postman dobore 62 laters Monday. He dered 245 frees on
nbery, How many elas da too sol? "Wes he on Monday. Hew mony ers he dlr on Tuesday?
15 Kimber sold 597 tat fora conc. Stove sol 216 fever hekets hon ©. Aposiman dered 602 laters on Mondoy He dred 245 noc ters on
Ember How many hts id Seve sl” “uesoy han on Honey. How many leer ihe Sever on Tues3ay?
12 caeregnnnet cmnneaiomannentedtme nei