Any number is said to be divisible by 13, when you add “four times of ones digit” with the remaining number, and the result is divisible by 13.

For example: Is 325 divisible by 13?

Step 1: Ones digit of 325 is 5, so the result = 32 + (4 x 5) = 32 + 20 = 52

Step 2: Check if result, 52 is divisible by 13.

Here, 52 ÷ 13 = 4, i.e. 52 is perfectly divisible by 13.

Hence, number 325 is divisible by 13.

Note: If the result obtained from above operation is a big number, then this technique can be continued till you get a smaller (may be upto 2 digit figures) numbers.

For example: Is 222222 divisible by 13?

Step 1: Figure 1: 22222 + (4 x 2) = 22230

Step 2: Figure 2: 2223 + (4 x 0) = 2223

Step 3: Figure 3: 222 + (4 x 3) = 222 + 12 = 234

Step 4: Figure 4: 23 + (4 x 4) = 39

As 39 is divisible by 13, so our number 222222 is also divisible by 13.

Practice Questions:

Check whether below numbers are divisible by 13?

a. 4566             b. 1246            c. 1040        d. 5642              e. 22124

f.  244               g. 3636             h. 975         i. 2860                j. 5551