Monday

To be able to add by counting on from the greater number.

Start by counting to 20 from 0. Then count on from given numbers.

This picture shows 9 aliens. Explain how you know.

Now we are going to add 4 more aliens. How many will there be? Explain how you know. My friend said you do not need to start counting from 1.

Does this knowledge help us to solve the problem below? 

Is it easier to start with the greatest or smallest number? 

Model problem 2 using a 100 square.