Question

Estimate each of the following using general rule:

(a) 730+998

(b) 796−314

(c) 12,904+2,888

(d) 28,292−21,496

Make ten more such examples of addition, subtraction and estimation of their
outcome​

Answer 1

• 730 + 998  :

Rounding off 730 to the nearest hundreds we get, 700

And rounding off 998 to the nearest hundreds we get, 1,000

Therefore, 700 + 1000 = 1,700

Therefore, estimate of 730+998 is equal to 1,700 according to the general rule.

• 796 – 314  :

Rounding off 796 to the nearest hundreds we get, 800

And rounding off 314 to the nearest hundreds we get, 300

Therefore, 800 - 300 = 500

Therefore, estimate of 796 – 314 is equal to 500 according to the general rule.

• 12,904 +2,888  :

Rounding off 12,904 to the nearest thousands we get, 13,000

And rounding off 2,888 to the nearest thousands we get, 3000

Therefore, 13,000 + 3,000 = 16, 000

Therefore, estimate of 12, 904 + 2,888 is equal to 16,000 according to the general rule.

• 28,292 – 21,496 :

Rounding off 28,292 to the nearest thousands we get, 28,000

And rounding off 21,496 to the nearest thousands we get, 21,000

Therefore, 28,000 - 21,000 = 7,000

Therefore, estimate of 28,292 - 21,496  is equal to 7,000 according to the general rule.