Two-digit addition 

Most of us learn to add on paper from right to left. And it is fine when doing math with paper and pencil. However, if you want to add 2-digit numbers fast in your head, it is better to add from left to right.

Example #3

   56
+ 23

A quick way to add 56 and 23 is to follow the 3 easy steps below:

Step 1:

Rewrite 23 as 20 + 3.

Step 2:

Add 56 and 20 since it is easy to add tens. You get 76.

Step 3:

Finally, just add 3 to 76 and the answer is 79.

Example #4

    64
+  35

Step 1:

Rewrite 35 as 30 + 5.

Step 2:

Add 64 and 30 and you get 94

Step 3:

Finally, just add 5 to 94 and the answer is 99