First you explain what the dividend, the divisor, and the approximately equals sign is. Then you tell the students that with estimated division you always look for a dividend that is divisible by the divisor. Tell that estimated division is different than estimated addition or subtraction, where you can more easily round to rounder numbers. With estimated division you cannot use all round numbers. You show how estimating division problems works step by step. Explain that you first look at the numbers in the table of the divisor. Find which outcome is the closest to the dividend. After that you can solve the problem. Next the students practice finding the division problem that is closest to the estimated division problem. After this, the students are going to estimate division problems on their own. For this, explain that it is sometimes possible to round the dividend to a tens- or hundreds number. Show this step by step through the problem 323 ÷ 4 ≈. Then have the students estimate the following problems on their own and ask how they rounded the dividend. After this, you discuss as a group whether the answers are more or less than the estimate and how you can know that. Then walk through the steps of solving an estimated division problem in a story problem
Check whether the students can estimate division problems by asking them the following questions:
- When is it useful to estimate quotients?
- What do you need to pay attention to when estimating division problems?