In this Grade 5 lesson from enVision Mathematics Chapter 5, students learn how to estimate quotients when dividing by 2-digit divisors using compatible numbers. They practice replacing dividends and divisors with nearby numbers that divide evenly, making mental math easier, and then use multiplication to check the reasonableness of their estimates. Real-world problems, such as finding the cost per item or dividing objects into equal groups, give students context for applying this estimation strategy.
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.