Adding, Subtracting, Multiplying, and Dividing Decimals! And a few fractions

Multiplication

100

When you multiply decimals you should first ignore the ________ ______?

Decimal Points

200

After multiplying the two decimals how do you decide how many decimal places the answer will have?

Count up the number of decimal places in the problem.

300

.2 x 3

.6

400

.02 x 11

.22

500

.21 x 11

2.31

Division

100

When you divide decimals you should first move the decimal point in the divisor (the number outside the division bar) to the ______________________?

Far right (just past the ones place)

200

After I move the decimal point in the divisor to the far right (the number outside the division bar), I move the decimal point in the dividend (the number inside the division bar) where? And where do I put the decimal point in the answer?

Move the decimal point in the dividend the same number of places you moved it in the divisor. Then move the decimal point straight up in the quotient/answer spot.

300

Divide 2.4 by .2 Remember the first number goes under the division bar.

12

400

Divide 24.3 by .03

810

500

Divide 6.48 by .4

16.2

Addition

100

When you add decimals you should first line up the __________ ___________. Then add some ______ if you need them.

Decimal Points zeros

200

2.23 + 4.1

6.33

300

1.33 + .2

What is -3.67

400

2.11 + 5.2

7.31

500

3.66 + 44.1

47.76

Subtraction

100

When you subtract decimals you should first line up the ________ _______? Then add some _______ if you need them.

decimal points zeros

200

2.44 - 1.1

1.34

300

34.67 - 2.1

32.57

400

5.33 - .2

5.13

500

22.567 - 1.22

21.347