Divisibility Rules

1. Divisibility Rules

2. DIVISIBLE • A number that can be divided by another number evenly • Divisibility rules allow you to identify if one number is divisible by another number quickly without using a calculator • Factors are numbers that are multiplied to form another number (2 and 4 are factors of 8)

3. RULES FOR 2, 5, AND 10 • The divisibility rules for 2, 5, 10 are as follows: • 2- a number is divisible by 2 if the number ends in an even digit (0, 2, 4, 6, or 8) • 5- a number is divisible by 5 if the number ends in a zero or a 5 • 10- a number is divisible by 10 if the number ends in zero

4. EXAMPLE #1 • Determine if 2, 5, 10 are factors of the number 45 672 978 • Solution: • The last digit is even, so the number is divisible by 2. • The last digit is not 0 or 5, so the number is not divisible by 5 and 10 • Therefore, only 2 is a factor of 45 672 978

5. EXAMPLE #2 • Determine if 2, 5, 10 are factors of the number 812 938 275. • Solution: • The last digit is odd, so the number is not divisible by 2. • The last digit is 5, so the number is divisible by 5 and 10.

6. YOUR TURN • Explain whether the number 239 is divisible by 2 • Explain whether the number 2345 is divisible by 5 • Explain whether the number 3330 is divisible by 5

7. Using a Venn diagram, sort the numbers that are divisible by 5 and 2 830 938 285 4837 8 372 045 Divisible by 5 Divisible by 2 8356 830 938 285 8356 847 240 847 240 8 372 045 4837

8. Please do pg 6 • # 1, 2 • Stop and check • Continue to sheet • If you finish look at #5, 9, 11on page 6 • Think about question 3, 4, 7, and 10