1. How would you use estimation to find the answer to 2,860 ÷ 13?

2. In this lesson you will learn how to divide by estimating and adjusting the quotient.

3. Let’s Review Multiplication and division are inverse operations. 45 ÷ 9 = n n x 9 = 45 9 x n = 45

4. Challenging problems can be broken into smaller parts 20 x 13 20 = 2 x 10 I know that 20 is 2 times 10 I can multiply 13 x 2 and get 26 Then I can multiply 26 x 10 and get 260 26 x 10 = 260 13 x 2 = 26 20 x 13 = 260

5. Let’s Review A Common Mistake Dividing with very small numbers 1,215 ÷ 10 Running totalQuotient 1,215 608 2 -(2x10)=20 1,196

6. Let’s Review Core Lesson 2,860 ÷ 13 Smart rounding ≈ 2,400 ÷ 12 Smart estimate ≈ 200 24 divides easily by 12

7. Let’s Review Core Lesson 2,860 ÷ 13 This makes sense since our smart estimate was 200 This makes sense since our smart estimate was 200 Running total Quotient 2,860 10 x 13= 130 100 x 13= 1,300 200 x 13 = 2,600 -(200 x 13) = 2,600 260 200 13 x 1= 13 13 x 2 = 26 13 x 20 = 260 -(20 x 13) =260 0 20 220

8. Let’s Review Core Lesson There are 1,716 stamps for 16 students. How many stamps does each student get? Smart rounding ≈ 1,600 ÷ 16 Smart estimate ≈ 100 1,600 divides easily by 16

9. Let’s Review Core Lesson 1,716 ÷ 16 This makes sense since our smart estimate was 100 This makes sense since our smart estimate was 100 Running total Quotient 1,716 10 x 16= 160 100 x 16= 1,600 -(100 x 16) = 1,600 116 100 10 x 16= 160 Too large 5 x 16 = 80 -(5 x 16) =80 36 5 2 x 16 = 32 -(2 x 16) =32 4 left 2 107

10. In this lesson you have learned how to divide by estimating and adjusting the quotient.

11. Let’s Review Guided Practice Use estimation and adjustment to solve 2,860 ÷ 13. Running total Quotient 2860

12. Let’s Review Extension Activities Use estimation and adjustment to solve 2,575 ÷ 23. Explain your work. Susanna is sorting her giant button collection into boxes. She wants each box to have the same number of buttons. She has 3,920 buttons. If she has 15 boxes, how many buttons will she put in each box. Will she have any left over?

13. Let’s Review Quick Quiz Which table shows how to divide 1,655 ÷ 15? Running total Quotient 1,655 -(100 x 15)=1500 100 155 -(10 x 15) = 150 10 5 left110 Running total Quotient 1,655 -(9 x 112)=1008 112 647 -(40 x 15) = 600 40 47 left152 Running total Quotient 1,655 -(100 x 16)=1600 100 55 -(10 x 5) = 50 10 5 left110 AB C

14. Let’s Review Quick Quiz Which table shows how to divide 1,248 ÷ 12? Running total Quotient 1,248 -(100 x 12)=1,000 100 248 -(12 x 20) =240 10 58 left110 Running total Quotient 1,248 -(12 x 100)=1,200 100 48 -(12 x 4) = 48 4 0104 Running total Quotient 1,248 -(100 x 12)=1,100 100 148 -(12 x 12)= 144 10 4 left110 AB C