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