In this Grade 5 Eureka Math lesson from Chapter 12, students learn to divide two- and three-digit dividends by two-digit divisors to produce single-digit quotients using the standard long division algorithm. Students practice estimating quotients by rounding divisors to the nearest multiple of ten, then verify their answers using multiplication and addition. The lesson builds fluency with problems such as 72 ÷ 21 and 156 ÷ 43, connecting mental estimation strategies to a written method.
Section 1
Using Compatible Numbers to Estimate Quotients
To estimate a quotient, first round the divisor to the nearest ten.
Then, find a compatible number for the dividend that is close to the original dividend and can be easily divided by the rounded divisor.
This estimation can be represented as , where is the rounded divisor and is the compatible dividend.
Expand to review the lesson summary and core properties.
Section 1
Using Compatible Numbers to Estimate Quotients
To estimate a quotient, first round the divisor to the nearest ten.
Then, find a compatible number for the dividend that is close to the original dividend and can be easily divided by the rounded divisor.
This estimation can be represented as , where is the rounded divisor and is the compatible dividend.