Decimal Rule
Addition of Decimals
Subtraction of Decimals
Multiplication of Decimals
Area Models
100
How do you add decimals?
You line up the decimals and then add the numbers.
100
58.9 + 3.04 =
61.94
100
3.95 - 2.7 =
1.25
100
.6 x 2.1 =
1.26
100
What is the missing number?
28
200
How do you subtract decimals?
You line up the decimals and then subtract the numbers.
200
.004 + 5.1 =
5.104
200
95.29 - 1.3 =
93.99
200
4.25 x 21 =
89.25
200
What is the area of this model?
240
300
What do you do if there are not enough digits in the top number to subtract a problem?
You have to add on zero's.
300
.9843 + 2.67 =
3.6543
300
125 - .68 =
124.32
300
.03 x .03 =
.0009
300
What are the missing numbers for each region in the rectangle?
2, 0.4,0.6,0.12
400
How do you multiply decimals?
You multiply the numbers and then you add the decimal after.
400
5 + 2.78 + .030 =
7.81
400
.468 - .059 =
.409
400
2.003 x .05 =
.10015
400
What is the area of this model?
3.00
500
How do you correctly read this number? 2.7450
Two and seven-thousand, four-hundred and fifty ten-thousandths.
500
8.07 + .0976 + 23.3 + 48 =
79.4676
500
5.45 - 3.799 =
1.651
500
.312 x 1.67 =
.52104
500
What would be the missing numbers on the outside of this rectangle if the rectangle was (0.45) x (0.23)
0.4 and 0.05
0.2 and 0.03