Explain to students how you can add. First is to add by counting. You first count how many you have, that is your first addend, and then you count how many more are joining, your second addend. When you count them together, you get the sum, or total of the two addends together. You can demonstrate this with the dots and cherries on the interactive whiteboard. Check that students understand this by asking them to add the money together. Ask them what total they get. Next, explain how you can add using support from blocks, a rekenrek, or the number line. Explain that it is easy to first make ten before adding the rest of the number. Have students practice this as well. Finally, show them how to solve a story problem. First they determine what kind of problem it is, then which numbers are needed from the story, to say the problem, and then to solve the problem. Have students solve the story problem.
Check that students understand adding to 20 by asking the following questions:
- What is useful if you want to add on the number line?
- What do you look at if you want to solve a story problem?
- How do you calculate the sum of 8+7?