5th Grade Module 2 – Lesson 21 Lesson 21: I can divide two and three digit dividends by two digit divisors with single digit quotients and make connections to a written method. 5th Grade Module 2 – Lesson 21

Divide by Two Digit Numbers 61 ÷ 17 Estimate Standard Algorithm 3 R10 61 ÷ 17 17 61 ÷ 20 60 -51 10 3 5th Grade Module 2 – Lesson 21

Divide by Two Digit Numbers 48 ÷ 21 Estimate Standard Algorithm 2 R6 48 ÷ 21 21 48 ÷ 20 40 -42 6 2 5th Grade Module 2 – Lesson 21

Divide by Two Digit Numbers 99 ÷ 32 Estimate Standard Algorithm 3 R3 99 ÷ 32 32 99 ÷ 30 90 -96 3 3 5th Grade Module 2 – Lesson 21

Divide by Two Digit Numbers 74 ÷ 37 Estimate Standard Algorithm 2 74 ÷ 37 37 74 ÷ 40 80 -74 2 5th Grade Module 2 – Lesson 21

Application Problem 105 students were divided equally into 15 teams. How many players were on each team? If each team had 3 girls, how many boys were there altogether? Solution on next slide… 5th Grade Module 2 – Lesson 19

5th Grade Module 2 – Lesson 21 Solution 7 15 105 -105 7 players on each team 3 girls and 4 boys 5th Grade Module 2 – Lesson 21

256 ÷ 47 Standard Algorithm 5 R21 47 256 -235 21 ≈ 250 ÷ 50 ≈ 5 Concept Development 256 ÷ 47 Let’s use rounding to find an estimated quotient! ≈ 250 ÷ 50 ≈ 5 How did our estimate help us with the standard algorithm? Standard Algorithm 5 R21 47 256 -235 21 5th Grade Module 2 – Lesson 21

236 ÷ 39 Standard Algorithm 6 R2 39 236 -234 2 ≈ 240 ÷ 40 ≈ 6 Concept Development 236 ÷ 39 Think on your own! How will you estimate? ≈ 240 ÷ 40 ≈ 6 How did our estimate help us with the standard algorithm? Standard Algorithm 6 R2 What is the difference between our estimate and our actual answer? 39 236 -234 2 5th Grade Module 2 – Lesson 21

369 ÷ 46 Work independently to estimate the quotient. Check your work with your partner. Solution (use ink tools): 5th Grade Module 2 – Lesson 21

712 ÷ 94 Work independently to estimate the quotient. Check your work with your partner. Solution (use ink tools): 5th Grade Module 2 – Lesson 21

Get Ready to Complete the Problem Set on Your Own! Complete Pages 2.F.32 & 2.F.33 You will have 15 minutes to work. Try your Best! 5th Grade Module 2 – Lesson 21

5th Grade Module 2 – Lesson 21 LET’S Debrief What pattern did you notice between 1(c) and 1(d)? Since the quotient was 8 with remainder 7 for both problems, does that mean the two division expressions are equal to each other? In problem 1, did your estimate need adjusting at times? When? What did you do in order to continue dividing? Share your thought process as you solved Problem 2. How many solutions might there be to this problem? Can you create another solution to it? How did your understanding of the check help you? How does estimating make the process of long division more efficient? 5th Grade Module 2 – Lesson 21

5th Grade Module 2 – Lesson 21 EXIT TICKET Page 2.F.34 5th Grade Module 2 – Lesson 21