Estimation of a whole-number quotient involves replacing a dividend, and when useful the divisor, with nearby compatible numbers that are easy to divide mentally while preserving a reasonable quotient size. For example, 283 ÷ 7 can be estimated as 280 ÷ 7 = 40; the estimate is not necessarily exact and should be judged for reasonableness. The scope is one-digit divisors and whole-number dividends within 1,000, not multi-digit divisors, decimals, or fractions.
To estimate a quotient, replace the dividend with a nearby number that is easy to divide by the divisor. This nearby number is called a compatible number.
Example: Estimate .
Find a number close to that is easy to divide by .
is close to , and is a multiple of .
Replace with :
Divide:
So, the estimate is:
This is reasonable because is very close to , so the quotient should be close to .
Click a topic below to practice the foundational skills you'll need, learn the steps, or master this skill
Earned ?