Page 23 - Math 4

Number System Number System

b) Now round off 26 to the nearest tens.
20 21 22 23 24 25 26 27 28 29 30
26 is close to 30.

So, rounding off 26 to the nearest tens is 30.

c) Round off 142 to the nearest tens.

142 is close to 140.
140 141 142 143 144 145 146 147 148 149 150
So, rounding off 142 to the nearest tens is 140.

d) Round off 278 to the nearest hundreds.

278 is closer to
300 than 200. So, 200 210 220 230 240 250 260 270 280 290 300
rounding off 278 to 278
the nearest hundreds is 300.

Now, can you tell the general rules for rounding off a number to the nearest
tens and hundreds? Discuss with your friends.

Exercise - 1.3

Section A - Classwork

1. Let's use number lines and round off the numbers to the nearest tens.

a) Rounding off 4 is
0 1 2 3 4 5 6 7 8 9 10

b) Rounding off 7 is
50 51 52 53 54 55 56 57 58 59 60
c) Rounding off 53 is

130 131 132 133 134 135 136 137 138 139 140
d) Rounding off 135 is

2. Let's use number lines and round off the numbers to the nearest hundreds.

a) Rounding off 140 is
100 110 120 130 140 150 160 170 180 190 200

b) Rounding off 260 is
200 210 220 230 240 250 260 270 280 290 300

21
21
vedanta Excel in Mathematics - Book 4
Approved by Curriculum Development Centre, Sanothimi, Bhaktapur v edanta Ex c e l in Mathematics - Book 4