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!

Fill in the Blanks

What is the sum of the digits of 1,402?

Fill in the Blanks

What is the sum of the digits in 5,402?

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