Step by step
The question
Question: is 73 divisible by 3?
Divisible means it goes in exactly, with nothing left over.
1 Add the digits
We add the digits: 7 + 3 is 10.
Why add the digits?
Each ten is 9 and 1 more.
Each hundred is 99 and 1 more.
3 and 9 go into the 9s and 99s.
What is left over is the sum of the digits.
For 3: 10 divided by 3 is 3, with 1 left over.
So 3 does not go into 73.
Careful!
For 3, the last digit does not tell us.
73 ends in 3, but 3 does not go in.
We add the digits.
2 Write the answer
So 73 is not divisible by 3.
3 Check
Let's check by dividing.
73 divided by 3 is 24, with 1 left over.
The tests were right!
Let's look back.
First: add the digits.
Then: write the answer.
Last: check.