In preparing students for the concept of fact families, this lesson shows how we can get two different subtractions from one addition, using visual models. It also ties in with the connection between addition and subtraction.
For example, if we have 4 and 2 marbles, it makes a total of 6. From that 6, we can either subtract the 4, leaving 2 — or we can take away the 2, leaving 4. The picture is a very powerful aid in helping children understand this!
We also solve some simple true/false statements and word problems in the latter part of the lesson.
If you cannot see the video above, click here for an alternative video player.
The connection between addition and subtraction — video lesson for 1st grade math
Math Mammoth Grade 1 curriculum