I explain two basic strategies for mental addition, using several examples. The first one is that of adding in parts. For example, to add 36 + 47, we can add 30 and 40, and 6 and 7. Since 6 + 7 = 13, this problem becomes 30 + 40 + 13, which is easier than the original.

Another strategy is to use a fact you already know to solve a similar addition problem. For example, if you already know that 6 + 8 = 14, you can use that to solve 76 + 8 or even 60 + 80.

The 2nd part of this lesson on mental math strategies is here:
   • Strategies for mental math: use an ea...  
In it, I show you how to use an easier problem (a helping problem so to speak).

Practice your mental addition skills with this free hidden picture game:
https://www.mathmammoth.com/practice/...
Choose a number range within two-digit numbers.

Here are simple online practice problems for mental addition:
https://www.mathmammoth.com/practice/...

This lesson is part of the Math Mammoth Grade 3 curriculum:
https://www.mathmammoth.com/complete/...