Show:
multiplying decimals
dividing decimals by whole number
multiplying decimals by whole number
using the strategies
decimal
100
0.3 X 0.2 =
0.06
100

4.5 / 3 =

1.5

100
0.2 x 2 =
0.4
100
if you are using the strategy multiplying decimals, what would be an easy way to do that?
Multiply normally, ignoring the decimal points. Then put the decimal point in the answer - it will have as many decimal places as the two original numbers combined.Count up how many numbers are after the decimal point in both numbers you are multiplying, then the answer should have that many numbers after its decimal point.
100

what is a decimal?

parts of a whole based on the number ten, tenth parts, and powers of ten.

200

1.2 x 0.004 =

0.0048

200

1.2 / 6 =

0.6

200
0.8 x 4 =
0.32
200

if you are dividing decimals and some one asked you how to do that how would you explain?

The trick is to convert the number you are dividing by to a whole number first, by shifting the decimal point of both numbers to the right

200
what happens to a decimal when it is multiplied by 10?
the decimal moves to the right one time
300

1.57 x 0.02 =

0.03

300

10.24 / 2 =

5.1

300

1.2 x 3.1 =

3.6

300
if you are dividing a decimal by a whole number what is the first step you would do?
Move outside decimal all the way to the right
300
what happens to a decimal when it is 1/10 of the original?
the decimal moves to the left once
400

5.0 x 3.32 =

16.6

400

2.48 / 8 =

0.31

400
3.5 x 5 =
17.5
400

how do you solve addition and subtraction with decimal problems?

line up the decimals?

400
what happens to a decimal when it is multiplied by 100?
the decimal moves to the right twice
500

0.153 x 0.5 =

0.0765

500

120.8 / 4 =

30.2

500

124.27 x 2 =

248.54

500

do you have to line up the decimals in a multiplication problem?

No! Ignore them first. Add them in at the end.
500
what happens to a decimal when it is multiplied by 1,000?
the decimal moves to the right three times