Page 45 - Maths Class 05

Example : Estimate the product of 475 and 326 to the nearest hundred.

Solution : Rounding off
475 to the Nearest 500
Hence, estimated product of 475 and 326
100
326 Nearest 300 = 500 × 300 = 150000
100

Example : Estimate the product of 679 and 257 by rounding off the first number
upwards and second number downwards.

Solution : Rounding off
679 700
upwards
Hence, estimated product of 679 and 257

257 downwards 200 = 700 × 200 = 140000

Example : 50,675 buttons are to be packed in packets. Only 25 packets are available.
How many buttons should be packed in each packet ?

Solution : Actual Quotient :

2027 buttons

25 5 0 6 7 5 0 0 0
Estimated Quotient :
– 5 0 0 0 0 0 0 0
Number of buttons = 50000
0 6 7 0 0 0 0
Number of packets = 25
– 5 0 0 0 0 0
50000
1 7 5 0 0 0 Buttons in each packet = = 2000 buttons.
25
– 1 7 5 0 0 0
0 0 0

Practice - 2.10
Practice - 2.10
Practice - 2.10
Practice - 2.10
1. Estimate each of the following to the nearest ten by showing actual sum.
a. b. c. d.
6 8 2 6 9 1 0 2 6 8

+ 2 4 + 1 3 + 3 8 2 + 1 4 8

2. Estimate each of the following to the nearest hundred by showing actual sum.

a. b. c. d.
4 1 7 5 2 9 3 4 9 8 3 3 5 0
+ 3 5 9 + 6 8 4 + 6 5 2 8 + 4 3 9 7

Mathematics-5 45