1. Chapter 5: Divide Decimals
Standards: MAFS.5.NBT.1.2 ,MAFS.5.NBT.2.7

2. Vocabulary Words
compatible numbers numbers that are easy to compute with mentally
decimal a number with one or more digits to the right of the decimal point
decimal point a symbol used to separate the ones place from the tenths place in decimal numbers
dividend the number that is to be divided in a division problem
division the process of sharing a number of items to find how many equal groups can be made or how many items will be in each equal group; the opposite operation of multiplication
divisor the number that divides the dividend
estimate a number that is close to an exact amount
hundredth one of one hundred equal parts
tenth one of ten equal parts

3. 5.1: Division Patterns with Decimals
Look for a pattern.
Look for a pattern in these products and quotients.
560 x 1 = 560
560 x .01 = 5.60
560 x .001 = 0.560
560 x =
560 ➗ 1 = 560
560 ➗ 10 = 56.0
560 ➗ 100 = 5.60
560 ➗ 1,000 = 0.560
560 ➗ 10⁰ = 560
560 ➗ 10ٰ¹ = 56.0
560 ➗ 10² = 5.60
560 ➗ 10³ = ___

4. 5.1 Cont’d
225 ➗ 10⁰ =
225 ➗ 10ٰ¹ =
225 ➗ 10² =
225 ➗ 10³ =
➗ 1 =
156 ➗ 10 =
156 ➗ 100 =
156 ➗ 1,000 =
➗ 10⁰ =
86.3 ➗ 10ٰ¹ =
86.3 ➗ 10² =
86.3 ➗ 10³ =

5. 5.3 Estimate Quotients
You can use multiples and compatible numbers to estimate decimal quotients.
Estimate.
249.7 ➗ 31
Step 1 Round the divisor.
31 rounded to the nearest 10 is _______ .
Step 2 Round the dividend to a number that can be divided evenly by the divisor.
249.7 is between ______ and _______ .
Step 3 Divide and solve.
240 ➗ 30 = ______ ➗ 30 =
So, two possible estimates are ______ and _____.

6. 5.3 Cont’d Estimate the quotient. 338.7 ➗ 49 = _________
➗ 9 = _________
➗ 19 = _____

7. 5.4 Division of Decimals by Whole Numbers
Traditional/Old Fashion Method (i.e. the way your parents know how to solve these)

8. Review
What happens to the decimal point every time you divide by a power of 10?
67.8 ➗ 10⁰ =
67.8 ➗ 10ٰ¹ =
67.8 ➗ 10² =
3. Estimate the quotient.
89.6 ➗ 4 =
4. Divide.
➗ 62=
(Trailing Zero below)
➗ 0.6 =

9. 5.6 Divide Decimals
Step 1: Multiply both the dividend and the divisor by a power of 10 to make the divisor a whole number (or move the decimal over in the divisor… then the dividend).
Step 2: Divide as you would whole numbers. Place the decimal point in the quotient, above the decimal point in the dividend.
Ex:
Ex:

10. 5.6 Cont’d
45 ➗ 9 = ___
4.5 ➗ ___ = 5
______ ➗ = 5

11. 5.7 Zeroes in the Dividend (trailing zero)
When there aren’t enough digits, you can add zeroes to the dividend (if you are getting remainders).
Step 1: Divide as you would with whole numbers. Place the decimal point in the quotient above the decimal point in the dividend.
Step 2: The difference is less than the divisor. Write a 0 in the dividend to the right of the last digit and continue to divide.
Ex: 5.2 ➗ 8 =

12. 5.7 Cont’d
372 ➗ 15 =
➗ =
➗ 9 =