There are different ways to check multiplication. Some of the commonly used methods are:
Repeated addition which can be tedious
Multiplying by changing the order of factors
Estimation
Example: 25 x 3 = 69 Verification by repeated addition
25x 3 = 75
This can be verified as 25 + 25 + 25 = 125.
Hence verified.
Verification by changing the order of factors
25 x 3 can be written as 3 x 25
3 x 25 = 125
Hence verified.
Verification by estimation
25 can be approximated to 30.
Hence 30 x 5 = 150.
The original result 25 x 3 = 125.
125 can be approximated as 130.
Hence verified.