# Number Theory Flashcards

1

Q

Divisible by 2 test

A

Last digit divisible by 2

2

Q

Divisible by 3 test

A

Sum of digits divisible by 3

3

Q

Divisible by 4 test

A

Number formed by two final digits divisible by 4

4

Q

Divisible by 5 test

A

Last digit 0 or 5

5

Q

Divisible by 8 test

A

Number formed by final three digits divisible by 8

6

Q

Divisible by 9 test

A

Sum of digits divisible by 9

7

Q

Divisible by 11 test

A

Result of adding and subtracting digits in alternating order beginning at leftmost digit is divisible by 11