Number lines can go up to any number, such as 10, 20 ... can help you to add and subtract. When you are adding, it doesn't matter which order you put the numbers in the answer will always be ...

You can make this easier by taking away smaller amounts that add up to bigger numbers. There are two ways to find the answer to subtraction calculations. First, you could start on the smaller ...

I'm a first grade teacher and today I'm going to show you two strategies that we can use when we're adding numbers or subtracting numbers within the number 20. The first strategy is called make a 10.