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Math Gym
Number Theory Guide

Number Theory Level 29: Rules - all (small N). divisibility rule.

1. Check divisibility by 3

1. Check divisibility by 3
Use the rule for the selected divisor; do not trial-divide blindly.

Select the digits or multiple required by this divisor.

needs 3 and 4.

2. Check divisibility by 4

2. Check divisibility by 4
Check divisibility by 3

Apply the selected rule exactly.

sum 12, last two 20.

3. Both rules decide

3. Both rules decide
Check divisibility by 3
Check divisibility by 4
Yes

Read the divisibility relation and its semantic answer.

answer yes.