Multiplication Tips and Tricks

Example: 22 x 21<br>
Step 1: Write your problem down.<br>
2 2 <br>
x 2 1<br>
------------<br>
Step 2: Multiply & write your problem down.<br>
2 2
x 2 1
----------
2
Step 3: Now, do the cross multiplication.
2 2
x 2 1
----------
2
Step 4: Add the products from the previous step
2 x 2
+ 2 x 1
------------
6
Step 5: Multiply again (Mention previous step's value in middle of the solution)
2 x 2
+ 2 x 1
------------
4 6 2