Cambridge International Mathematics

22 Assumed Knowledge (Number)

²

Look at theseconddecimal place.

If the digit is 5 , 6 , 7 , 8 or 9 , roundup.

If the digit is 0 , 1 , 2 , 3 or 4 , rounddown.

²

Look at thethirddecimal place.

If the digit is 5 , 6 , 7 , 8 or 9 , roundup.

If the digit is 0 , 1 , 2 , 3 or 4 , rounddown.

Example 29 Self Tutor

Round 39 : 748 to the nearest:

a whole number b one decimal place c two decimal places

a 39 : 748 ¼ 40 to the nearest whole number

b 39 : 748 ¼ 39 : 7 to one decimal place

c 39 : 748 ¼ 39 : 75 to two decimal places

Notice that: 0 : 5464 ¼ 0 : 546 (to 3 decimal places)

¼ 0 : 55 (to 2 decimal places)

¼ 0 : 5 (to 1 decimal place)

1 Round to the nearest whole number:

a 0 : 813 b 7 : 499 c 7 : 500 d 11 : 674 e 128 : 437

2 Write these numbers correct to 1 decimal place:

a 2 : 43 b 3 : 57 c 4 : 92 d 6 : 38 e 4 : 275

3 Write these numbers correct to 2 decimal places:

a 4 : 236 b 2 : 731 c 5 : 625 d 4 : 377 e 6 : 5237

4 Write 0 :183 75correct to:

a 1 decimal place b 2 decimal places c 3 decimal places d 4 decimal places

Example 30 Self Tutor

Find^27 correct to 3 decimal places.

0 : 2857

7 2 : (^0604050) )^27 ¼ 0 : 286
5 : 64
look at this
then round
5 : 648
look at this
then round
EXERCISE H.1
Rounding to the nearest one decimal place
Rounding to the nearest two decimal places
IGCSE01
cyan magenta yellow black
(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_as\022IGCSE01_AS.CDR Tuesday, 18 November 2008 12:09:00 PM PETER
(Page included on the Student CD only)