Mental Math & Number Tricks

Three is a _____________ of 21.

• variable

• sum

• factor

• half

Tags

CCSS.4.OA.B.4

A prime number is a number with two unique factors (1 and itself).

Which set of numbers are prime numbers?

• 10, 20, 40, 60

• 1, 3, 5, 7

Tags

CCSS.4.OA.B.4

True or False.

Inverse operations are operations that undo each other?

• True

• False

Tags

CCSS.HSA.REI.A.1

Look at the mental math challenge picture and solve.

*Show your work on scratch paper for 2 points extra credit.

• 30
• 40
• 50
• 20

Tags

CCSS.5.OA.B.3

Look at the mental math challenge picture and solve.

*Show your work on scratch paper for 2 points extra credit.

• 2
• 4
• 6
• 8

Tags

CCSS.5.OA.A.1

CCSS.5.OA.A.2

Solve for the missing variable (x).

(5 × 3) + x = 19

• 2
• 10
• 5

• 4

Tags

CCSS.5.OA.A.1

CCSS.5.OA.A.2

I am a single-digit number. If you put a zero in my ones place, I will be equal to 5 + 5.

What number am I?

• 1
• 4
• 3
• 20

Tags

CCSS.1.NBT.B.2B

CCSS.1.NBT.B.2C

I am equal to 25 - 10 + 1 - 4 + 2 - 7.

What number am I?

*Show your work on your scratch paper to earn 1 extra credit point.

• 15
• 7
• 10
• 5

Tags

CCSS.7.NS.A.1C

Look at the mental math challenge.

What number represents the value of the banana?

• 8
• 6
• 2
• 4

Tags

CCSS.3.OA.D.8

True or False.

Number tricks DO NOT follow a set of rules.

• False
• True

Tags

CCSS.5.OA.B.3