Adding Numbers Within 100

Here's another one:

76+13

Stack the numbers and line things up in stripes:

76+13

Add down the stripes...

First, add the ones:

76+13

 Then, add the tens:


76+13

That's really

70+10=80

76+13=89

Here are some problems to practice.  Be sure to get really good at these before going to the next lesson.  You don't have to do ALL of them...  Just do as many as you need to until they feel easy.

1)  23+51   9)  39+50
2)  72+13 10)  52+14
3)  66+21 11)  73+25
4)  80+17 12)  22+13
5)  45+34 13)  17+42
6)  12+50 14)  83+15
7)  27+41 15)  23+41
8)  63+12 16)  66+11
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