Rules
Adding and Subtracting Decimals
Multiplying Decimals
Dividing Decimals
Surprise Questions
100
True or false:
In adding and subtracting you don't need to line up the decimals.
False
100
9.92 - 4.47
5.45
100
9.3 x 7
65.1
100
12.6 ÷ 3
4.2
100
0.3 as a percent
30%
200
True or False
When multiplying you don't need to line the decimals up.
True
200
68.99 - 62.56
6.43
200
8.9 x 3.2
28.48
200
32.4 ÷ 4
8.1
200
46.34 - 18.2 + 23.04
51.18
300
When subtracting decimals, what should you check before subtracting?
If the decimals are lined up
300
140.7 + 256.8
397.5
300
5.21 x 3.8
19.798
300
24.80 ÷ 2
12.4
300
Write two numbers that represent the shaded part.
65%
65/100
400
In what operation do you need to count how many decimal places/digits are behind the decimal?
Multiplication
400
The boys went to the toy store and spent $64.58 on legos. The girls went to the candy store and spent $32.73 on candy. How much money did the kids spend in all?
$97.21
400
A bottle of juice costs $3.75. If Jenny buys 4 bottles, how much money will she spend?
$15.00
400
Lila bought 3 packs of gum for $9.87 total. If each pack costs the same amount, how much did one pack of gum cost?
$3.29
400
After the decimal what are the place values called?
. _ _ _
tenths, hundredths, thousandths
500
When subtracting decimals, it is important to add these to make sure both numbers have the same number of places.
Zeroes
500
The bridge measured 143.5 meters high. The building measured 65.5 meters high. What is the difference in the heights of these two structures?
78 meters
500
A bakery uses 2.6 pounds of flour to make one batch of cookies. How much flour will they need to make 8.5 batches?
22.1 pounds of flour
500
Allen is making bookmarks for his friends. He has 84.6 meters of ribbon, and he wants to cut it into 6 equal pieces. How long will each piece of ribbon be?
14.1
500
Max is planning a birthday. He bought cookies for $4.55 and cupcakes for $12.20. At the register, he gave the cashier $20.00 How much change will Max get back?
$3.25