Middle School – Prime and Composite Numbers from 1-100

By | October 3, 2016

Prime and Composite Numbers

In this tutorial the students will learn how to classify the numbers from 1-100 as Prime, Composite or Neither.  Prime number have exactly 2 factors, 1 and itself.  Composite numbers have more than 2 factors.

Key Skills

Prime Numbers

Have exactly 2 factors, 1 and itself

Composite Numbers

Have more than 2 factors

Multiplication tables

Divisibility Rules

Rules on how to find out if a number is a divisor without having to do the divison.

Divisors

1: All numbers are divisible by 1.

2: All even numbers.  Even numbers have a 0,2,4,6, or 8 in the ones place.

3: The sum of the digits of the number is divisible by 3.

4: If the last 2 digits of the number are divisible by 4.

5: The digit in the ones place is a 5.

6: If the number is divisible by both 2 and 3.

8: If the last 3 digits of the number are divisible by 8.

9: If the sum of the digits of the number are divisible by 9.