Adding two positive numbers to each other makes things larger. When adding decimal numbers to each other, you add the numbers with the same place value together.
Rule
We usually say add together instead of plus or addition.
Example 1
You need to add 3 and 6 together.
Since both numbers are in the ones place, you can add them together directly. That gives you
Example 2
You need to add 12 and 25 together.
You can think like this:
The number has in the tens place and in the ones place.
The number has in the tens place and in the ones place.
First, you add the numbers in the ones place together. That gives you
Then you can add the numbers in the tens place together. That gives you
You have in the tens place and in the ones place. That makes the answer , which means that
Subtracting positive numbers from each other makes things smaller. When subtracing decimal numbers from each other, you subtract the numbers with the same place value from each other. We usually say to subtract from instead of subtraction.
Rule
Example 3
You need to subtract 6 from 9.
Since both numbers are in the ones place, you can subtract directly. That gives you
Example 4
You need to subtract 25 from 48.
In this case you can think like this:
The number has in the tens place and in the ones place.
The number has in the tens place and in the ones place.
First, you need to subtract the numbers in the ones place from each other. That gives you
Then you can subtract the numbers in the tens place from each other, which gives you
You now have in the tens place and in the ones place. That means the answer is