# Divisibility Rules 7 Math Section 3 3 Divisibility

Divisibility Rules 7 Math Section 3 -3

Divisibility Rules: What are they? l Rules to help you determine if numbers are divisible by other numbers. l Divisible – if a number can be divided by another number with no remainder, decimal, or fraction. l We will learn rules for 2, 3, 4, 5, 6, 8, 9, and 10.

Divisibility Rule for 2 l A number is divisible by 2 if… l The number is even. l Even numbers end in 2, 4, 6, 8, or 0. l Examples l 412 l 230 l 516

Divisibility Rule for 10 l A number is divisible by 10 if… l The number ends in a zero. l Examples l 4, 000 l 210 l 50

Divisibility Rule for 5 l A number is divisible by 5 if… l The number ends in a 5 or 0. l Examples l 4, 000 l 215 l 355

Divisibility Rule for 3 l A number is divisible by 3 if… l The sum of the digits of the number is divisible by 3. l Examples l 354 l 3 + 5 + 4 = 12 l 12 / 3 = 4 l 9, 363, 129 l 9 + 3 + 6 + 3 + 1 + 2 + 9 = 33 l 33/3 = 11

Divisibility Rule for 9 l A number is divisible by 9 if… l The sum of the digits of the number is divisible by 9. l Examples l 495 l 4 + 9 + 5 = 18 l 18 / 9 = 2 l 999, 918 l 9 + 9 + 1 + 8 = 45 l 45 / 9 = 5

Divisibility Rule for 6 l A number is divisible by 6 if… l The number is divisible by both 3 and 2. l Examples l 930 l 6000 l 216

Divisibility Rule for 4 l A number is divisible by 4 if… l The last 2 digits of the number is divisible by 4. l Examples l 9, 264 l 1, 209, 124 l 216

Divisibility Rule for 8 l A number is divisible by 8 if… l The last 3 digits of the number are divisible by 8. l Examples l 9, 808 l 8, 942, 216 l 848

Divisibility Rules l A number is divisible by: ¡ 2 if the number is even. ¡ 3 if the sum of the digits is divisible by 3. ¡ 4 if the last 2 digits of the number are ÷ by 4. ¡ 5 if the number ends in a 5 or 0. ¡ 6 if the number is divisible by 2 and 3. ¡ 8 if the last 3 digits of the number are ÷ by 8. ¡ 9 if the sum of the digits is divisible by 9. ¡ 10 if the number ends in a 0.

What number(s) is the number below divisible by? 27 3 and 9

What number(s) is the number below divisible by? 42 2, 3, 6

What number(s) is the number below divisible by? 215 5

What number(s) is the number below divisible by? 2, 848 2, 4, and 8

What number(s) is the number below divisible by? 9, 990 2, 3, 5, 6, 9, and 10

What number(s) is the number below divisible by? 17 None

Homework l Pages 143 -144 ¡(2 -40 evens) 18

- Slides: 18