1. © 2007 M. Tallman

2. compatible numbers When estimating division problems, rounding will not work very well. You must use compatible numbers. Compatible numbers Compatible numbers are numbers that contain a basic division fact… …8,100 ÷90, 720 ÷ 8, 144,000 ÷ 120

3. © 2007 M. Tallman 1. 120 ÷ 4 2. 3. 21,000 ÷ 7 4. 240 ÷ 6 5. 6. 7. 320 ÷ 8 8. 35,000 Find the compatible numbers in these division problems. 3,600 ) 9 → 12 ÷ 4 → 36 ÷ 9 → 21 ÷ 7 → 24 ÷ 6 → 42 ÷ 7 → 35 ÷ 5 → 32 ÷ 8 → 96 ÷ 8 4,200 ) 7 ) 5 9,600 ) 8

4. © 2007 M. Tallman 5 45 0 437 ÷ 9 9 ÷= 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers. Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 1 - 0 = 1 0 1 zero in the quotient

5. © 2007 M. Tallman 7 49 0 508 ÷ 7 7 ÷= 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers. Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 1 - 0 = 1 0 1 zero in the quotient

6. © 2007 M. Tallman 0 7224 3 21 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers. Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 1 - 0 = 1 0 ) 7 ) 1 zero in the quotient

7. © 2007 M. Tallman 7 4,2 0 4,324 ÷ 6 6 ÷= 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 2 - 0 = 2 0 0 2 0 2 2 zeros in the quotient

8. © 2007 M. Tallman 3,200 43,105 8 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers. Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 2 - 0 = 2 0 ) 4 ) 0 2 2 2 zeros in the quotient

9. © 2007 M. Tallman 4,000 54,175 8 1 1 Step 1: Look at the first couple of numbers of the dividend and the first number of the divisor. Step 2: Find the closest basic division fact to these numbers. Step 3: Use the basic fact to change the dividend and divisor in to compatible numbers, and divide. 0 2 - 0 = 2 0 ) 5 ) 0 2 2 2 zeros in the quotient Tip: Do not count the zero in 40.

10. © 2007 M. Tallman Estimate 468 ÷ 8 Division Fact:_________ Estimate:____________ 480 ÷ 8 = 80 48 ÷ 8 = 8

11. Estimate Division Fact:_________ Estimate:____________ 5,500 ÷ 5 = 1,100 55 ÷ 5 = 11 5,620 ÷ 5

12. © 2007 M. Tallman Estimate Division Fact:_________ Estimate:____________ 2,000 ÷ 4 = 500 20 ÷ 4 = 5 2,198 ÷ 4

13. © 2007 M. Tallman Estimate Division Fact:_________ Estimate:____________ 360 ÷ 12 = 30 36 ÷ 12 = 3 358 ÷ 12

14. © 2007 M. Tallman Estimate Division Fact:_________ Estimate:____________ 1,800 ÷ 9 = 200 18 ÷ 9 = 2 1,976 ÷ 9