Work It Out

1. Work It Out • You are asked to solve a few problems and determine a trick that can be used to divide a decimal by a decimal. By solving these problems with a calculator you quickly see a pattern to make an easy way to always divide. Explain that pattern and the new “trick” your peers can use for it. • 1) • 2)

2. Ideas?

3. When the divisor is a decimal, move the decimal point to the right in the divisor until it becomes a whole number. 

4. The number of places you moved the decimal in the divisor, move the decimal the same number of places in the dividend. 

5. After moving the decimals in both the divisor and dividend, this is your new division problem. 

6. Now let’s divide. Bring the decimal straight up into the quotient. .

7. Then divide. 1. 25

8. Subtract and bring down the next number. 1. 25 225

9. Finish dividing the problem. 1.9 25 225 225 0

10. Quick! • Why does this work?

11. Let’s try another example.

12. Move the decimal point to the right in the divisor until it becomes a whole number.  Move the decimal the same number of places in the dividend. 

13. After moving the decimals in both the divisor and dividend, this is your new division problem. 

14. Bring the decimal point straight up into the quotient. .

15. Let’s divide! .1 1 2

16. Subtract and bring down. .1 1 2 24

17. Finish dividing. .1 2 1 2 24 24 0

18. Now let’s try some on your own! 1) 2) 3) 4)

19. Answers 1) .079 2) 19.7 3) 9.1 4) .22

20. Let’s split! • Work it out in a race!!!

21. After a while crocodile • Agendas: PB pg21# 1-9 Choose 4, # 10 and 11