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How to Compare Decimal Numbers

BY CIVIL SERVICE REVIEWER FEBRURY !"# $%!&

We 'a(e alrea)* lear+e) 'ow to compare fractions a+) i+ t'is post# we are ,oi+, to lear+ 'ow to compare )ecimals- I+

compari+, )ecimals it is importa+t to u+)ersta+) place (alue- I+ t'e +umber $!.-/0"# t'e 1ollowi+, are t'eir place (alues-

For t'e w'ole +umbers#

$ 2 'u+)re)

! 2 te+s

. 2 o+es-

For t'e )ecimal +umbers#

/ 2 te+t's

0 2 'u+)re)t's

" 2 t'ousa+)t's

I+ w'ole +umbers# clearl*# t'e lar,er t'e +umber o1 )i,its t'e lar,er t'e +umber- For e3ample# 0$! 4 "$ si+ce 0$! 'as

t'ree )i,its a+) "$ 'as o+l* two )i,its- Si+ce w'ole +umbers are alwa*s ,reater t'a+ )ecimal +umbers i+compari+, )ecimal +umbers# loo5 at t'e w'ole +umbers 1irst- 6'ere1ore# we 'a(e t'e 1ollowi+, rule-

Rule 1: I+ compari+, )ecimal +umbers# loo5 at t'e w'ole +umber 1irst- 6'e )ecimal +umbers co+tai+i+, lar,er w'ole

+umbers 'a(e lar,er (alues-

E3ample ! 7 0/-$. 4 0$-./8 si+ce 0/ is ,reater t'a+ 0$-

E3ample $7 !$-8& 9 !8-%%! si+ce !$ is less t'a+ !8-

E3ample .7 !/!-08 4 !$.-/ because !/! is ,reater t'a+ !$.

Rule 2: I1 t'e w'ole +umbers are e:ual# t'e+ compare t'e +umbers b* loo5i+, at t'e te+t's place 1irst- 6'e +umber wit'

t'e lar,er )i,it i+ te+t's place is lar,er-

E3ample !7 !0-./ 4 !0-$! si+ce . 4 $-

E3ample $7 !$-"8 4 !$-!8 si+ce " 4 !-

E3ample .7 %- " 4 %-0;. si+ce " 4 0-

Notice t'at i+ Rule $ E3ample .# e(e+ i1 %-0;. 'as more )i,its# it is still less t'a+ %-" si+ce " is ,reater t'a+ 0 a+) t'e* are

i+ t'e te+t's place-

Rule 3:I1 t'e w'ole +umbers a+) t'e te+t's place are e:ual# t'e+ compare 1irst t'e 'u+)re)t's place- 6'e +umber wit'

t'e lar,er )i,its i+ t'e 'u+)re)t's place is t'e lar,er +umber-

Rules $ a+) . ca+ be ,e+erali

7/25/2019 How to Compare Decimal Numbers

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!-> ?a5e t'em positi(e

$-> ppl* t'e rules abo(e

.-> Re(erse *our a+swer-

E3ample7 Compare @0$-/8 a+) @0$-.!

!-> ?a5e t'em positi(e7 0$-/8 a+) 0$-.!

$-> ppl* t'e rules abo(e7

From t'e rules abo(e# t'e w'ole +umbers are bot' 0$# so we loo5 at t'e te+t's place- %-/ 4 %-.# so 0$-/8 4 0$-.!

Aperatio+s o+ Decimals

1. How to Add Numbers with Decimals

$- Example 1: 3.02 + 80.401

.- I+ a))i+, .-%$ a+) 0%-/%!# t'e )ecimal part o1 t'e 0%-/%! 'as more )i,its t'at t'at

o1 .-%$- But t'ere is +o +umber to t'e ri,'t o1 $# so we ca+ ust put %-

/- Remember t'at a))i+, % to t'e ri,'t 'a+) si