Divisibility Tricks

Divisibility Tricks

Lets' learn how to tell if a number is divisible by 2, 3, 5, and 10

All EVEN numbers are DIVISIBLE by 2

That means when you divide the number by 2 there are no remainders

Even numbers end in 0, 2, 4, 6, or 8

Multiple Select

Select all the numbers divisible by 2

• 16

• 25

• 1,350

• 998

Open Ended

Type in 3 examples of numbers that are NOT divisible by 2

Divisibility Trick for 3

• add (find the sum) of the digits
• Is that sum divisible by 3?
• If yes, so is the number!

Multiple Select

Select ALL of the numbers divisible by 3.

• 57

• 315

• 1,004

• 824

How to tell if a number is DIVISIBLE by 5

the number ends in a zero or 5

Multiple Select

Select ALL of the numbers divisible by 5.

• 83

• 900

• 145

• 15,556

How to tell if a number is DIVISIBLE by 10

• if the number ENDS in ZERO

Open Ended

Type 3 numbers, bigger than 100 that is DIVISIBLE by 10

Simplifying or Reducing Fractions

• You have to divide the numerator (top) and denominator (bottom) by the SAME number

Multiple Choice

What do you get when you reduce 14/16?

• 7/8

• 7/9

• 7/16

• it does not reduce

Reducing or Simplifying Fractions

• when you reduce you look for the LARGEST number that can divide evenly into the numerator (top) and denominator (bottom)

Multiple Choice

What is the Largest Number you could reduce 9/15 by?

• 5

• 3

• 2

• 6

Multiple Choice

What is the largest number you could reduce 20/50 by?

• 2

• 5

• 10

• 20