Addition
0.95 + 5.09 =
6.04
5.68 - 4.23 =
1.45
8 x 6.5 =
52
5.6 X 10
56
For which 2 operations (addition, subtraction, multiplication) do you need to line up the decimal points?
Addition and Subtraction
11.27 + 9.4 =
20.67
67.75 - 8.1 =
59.65
4.2 x 1.8 =
7.56
2.45 X 100
245
For which operation (addition, subtraction, multiplication, division) do you need to count the total decimal places of the factors, in order to correctly place the decimal point in the answer?
Multiplication
9.6 + 0.18 =
9.78
43.03 - 6.912 =
36.118
3.7 x 0.8 =
2.96
156 X .01
1.56
How many places would there be after the decimal in the product of 1.23 x 2.4
3 places after the decimal
1.23 + 8 + .005
9.235
12 - 4.61 - 2.35 =
5.04
0.07 x 0.4
0.028
23.1 X 5.7
131.67
Why is there only one number after the decimal in 1.2 x 3?
Because we only have one digit after the decimal (tenths times ones still equals a tenths place)
8 + 2.45 + 3.026
13.476
100 - 4.25 =
95.75
.23 x 0.001
0.00023
5.11 X 3.7
18.907
Why do we not line up the decimal places when we multiply?
every digit in one number gets multiplied by every digit in the other number