This is the very beginning of understanding how addition works.

Let's look at two sets:

Set A Set B
Set A: 2 triangles Set B: 3 triangles
Count how many
triangles are in Set A... There are 2!
Count how many
triangles are in Set B...
There are 3!

Now, put the sets together into one big set:

Set A and Set B get put together to make 5 triangles

Count how many triangles are in this set...
There are 5!

So, 2+3=5

 

 

 

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