1. 5th Grade Module 2 – Lesson 19
Lesson 19: I can divide two and three digit dividends by multiples of 10 with single digit quotients and make connections to a written method.
5th Grade Module 2 – Lesson 19

2. Estimate and Divide
908 ÷ 28
Estimate the value…
Say the divisor rounded to the nearest ten…
Name the multiple of 30 that’s closest to 900… ÷ 30
900 30
5th Grade Module 2 – Lesson 19

3. Estimate and Divide
Say the divisor rounded to the nearest ten…
Estimate the value…
Name the multiple of 30 that’s closest to 152…
152 ÷ 33 ÷ 30
150 5
5th Grade Module 2 – Lesson 19

4. Estimate and Divide
Say the divisor rounded to the nearest ten…
Estimate the value…
Name the multiple of 100 that’s closest to 398…
398 ÷ 98 ÷
100
400 4
5th Grade Module 2 – Lesson 19

5. Estimate and Divide
Name the multiple of 80 that’s closest to 7,272…
Say the divisor rounded to the nearest ten…
Estimate the value…
7,272 ÷ 81 ÷ 80
7,200 90
5th Grade Module 2 – Lesson 19

6. 5th Grade Module 2 – Lesson 19
Application Problem
At the Highland Falls pumpkin growing contest, the prize winning pumpkin contains 360 seeds. The proud farmer plans to sell his seeds in packs of 12. How many packs can he make using all the seeds?
Solution on next slide…
5th Grade Module 2 – Lesson 19

7. 5th Grade Module 2 – Lesson 18
Solution
Think of 360 as 36 tens…
360 ÷ 12 =
(36 ÷ 12) x 10 =
3 x 10 = 30 packets
5th Grade Module 2 – Lesson 18

8. 70 ÷ 30 70 ÷ 30 ≈ ÷ 30 Check: 30 x 2 = 60 70 30 Precise Answer: 2 R10
Concept Development
70 ÷ 30 70
What’s the whole (or dividend) in this problem?
Let’s use rounding to find an estimated quotient! 30
What’s the divisor?
Precise
Answer: 2 R10
70 ÷ 30
≈ ÷ 30
Check: 30 x 2 = 60
We are 10 off from 70!
10 is the remainder! 60 2
5th Grade Module 2 – Lesson 18

9. 430 ÷ 60 430 ÷ 60 ≈ ÷ 60 ≈ 7 Check: 60 x 7 = 420 430 60 Precise
Concept Development
430 ÷ 60
430
What’s the whole (or dividend) in this problem?
Let’s use rounding to find an estimated quotient!
Precise
Answer: 7 R10 60
What’s the divisor?
430 ÷ 60
≈ ÷ 60
≈ 7
Check: 60 x 7 = 420
We are 10 off from 430!
10 is the remainder!
420
7 groups of 60
5th Grade Module 2 – Lesson 19

10. Let’s Try That One Again Using the Standard Algorithm!
430 ÷ 60 =
R 10
Why is the 7 placed above the zero?
-420 10
Check:
60 x 7 = 420 (add the remainder!)
= 430
5th Grade Module 2 – Lesson 19

11. 572 ÷ 90 Work independently to estimate the quotient.
Check your work with your partner.
Solution (use ink tools):
5th Grade Module 2 – Lesson 18

12. Get Ready to Complete the Problem Set on Your Own!
Complete Pages 2.F.8 & 2.F.9 You will have 15 minutes to work. Try your Best!
5th Grade Module 2 – Lesson 18

13. 5th Grade Module 2 – Lesson 18
LET’S Debrief
Did anyone notice something different? Does it always make sense to use the standard algorithm?
In problem 2, what was Terry’s mistake? If you had to estimate the quotient, what would you have done? What could he do to correct his mistake without erasing his work so far?
What if Terry had estimated too large a quotient? What should he do?
How was solving Problem 3 different from solving all the others?
What did all our divisors have in common today? Did this make estimation easier?
5th Grade Module 2 – Lesson 18

14. 5th Grade Module 2 – Lesson 18
EXIT
TICKET
Page 2.F.10
5th Grade Module 2 – Lesson 18