Addition within 20
Lessons in this chapter
About Addition within 20
Put Together is the first chapter where kids combine numbers rather than just count them, and it introduces addition as two different actions that give the same answer.
Add Numbers up to 20 by Putting Together and Finding More than a Number covers both models deliberately. Putting together is two groups joined into one, so three apples and four apples make seven. Finding more than a number is counting on from where you are, so four and three more is seven. Kids need both, because word problems are written in both kinds of language.
Work on Addition Facts up to 5 then asks for some of it to be known rather than worked out. The small facts, 2 + 3, 1 + 4, 2 + 2, are used so often that recalling them instead of recounting frees a child up to think about the harder part of a problem.
The chapter stays within 20 and does not carry into regrouping, which is 1st grade's job. What it establishes is the meaning of addition, and the habit of counting on from the larger number rather than starting at one every time.
Both lessons open as worksheets in the page: Add Numbers up to 20 by Putting Together and Finding More than a Number, and Work on Addition Facts up to 5. The first gives math problems a child can solve by combining two groups, and the second is short enough to come back to daily until the facts are known by heart. Free to try, with no login needed for your first 3.
Frequently asked questions
Two lessons. Add Numbers up to 20 by Putting Together and Finding More than a Number introduces addition as two actions that give the same answer, combining two groups and counting on from one of them. Work on Addition Facts up to 5 then asks for the small sums by recall. This is the Common Core's Operations and Algebraic Thinking domain (K.OA), though the Common Core keeps kindergarten addition within 10, so the work above ten here runs a little ahead of it.
Two things at once: joining two groups into one, and counting on from a number. The first lesson teaches both, because problems are phrased in both ways and kids need to recognize each as addition.
Starting from one number and counting forward by the other, so 4 + 3 becomes five, six, seven. It is faster than counting every object from one, and it is the habit this chapter is trying to build.
The ones up to 5, so 1 + 1, 1 + 2, 2 + 2, 1 + 3, 2 + 3 and so on. Work on Addition Facts up to 5 is the lesson that drills them.
Because working out every small sum uses up all a child's attention. Once 2 + 3 is instant, that attention goes to the actual problem instead of the arithmetic inside it.
No. Fingers are a sound model and nearly every child uses them. Recall replaces them gradually as the small facts become familiar, which is what this chapter is working towards.