Add/Sub Concepts
When adding and subtracting the PLACE VALUES must match up. For example 4.5 + 2.3. The Five and the Three are both in THIS Place value.
What is the tenths place?
1.5 + 0.3
What is 1.8
5.4 - 2.1
What is 3.3?
14 x 2
What is 28?
1.2 x 3
What is 3.6?
You must do THIS before adding or subtracting decimals.
What is line up the decimal point?
54.1 + 1.02
What is 55.12?
7.46 - 4.2
What is 3.26
16 x 3
What is 48?
2.4 x 5
What is 12 or 12.0?
You can add this "number" to the far right side of a decimal and it won't change it's value.
For example if you wanted to add 4.15 and 3.2 you might add something after the "2"
What is a 0?
2.9 + 1.6
What is 4.5?
0.52 - 0.14
What is 0.38?
25 x 4
What is 100?
7.2 x 0.4
What is 2.88?
When adding sometimes we have to carry if the value is 10 or over.
When subtracting we might have to do THIS?
What is borrow?
9.08 + 1.99
What is 11.07?
2.22 - 0.55
What is 1.67?
36 x 7
What is 252?
0.54 x 0.6
What is 0.324?
When subtracting this number ALWAYS goes on top
What is the LARGER number?
12.5 + 4.61
7 - 3.62
63 x 8
What is 504?
0.33 x 0.02
What is 0.0066