Estimating Products in 2-Digit Multiplication

This video tutorial teaches grade four students how to estimate products in two-digit multiplication using mental math, rounding, and compatible numbers. The teacher explains the concept of compatible numbers, which are easy to compute mentally, and provides examples such as estimating the number of pudding cups sold in a month. The tutorial includes various examples and exercises to practice rounding and using compatible numbers for estimation, helping students perform calculations mentally and efficiently.

What is a compatible number?

• A number that is always odd

• A number that is always even

• A number that is difficult to compute

• A number that is easy to compute mentally

If you have four quarters, how much money do you have?

• $1.00

• $2.00

• $1.50

• $0.50

Tags

CCSS.4.MD.A.2

How many pudding cups are sold in 23 school days if 81 cups are sold each day?

• 1,600

• 1,900

• 1,800

• 1,700

Tags

CCSS.5.NBT.B.5

What is 26 rounded to the nearest compatible number?

• 20

• 30

• 25

• 40

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

What is 24 rounded to the nearest ten?

• 25

• 30

• 20

• 40

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

What is 79 rounded to the nearest ten?

• 75

• 70

• 80

• 90

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

What is 50 multiplied by 30?

• 1,400

• 1,200

• 1,500

• 1,300

Tags

CCSS.4.NBT.B.5

What is 52 rounded to the nearest ten?

• 55

• 60

• 50

• 45

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

What is 83 rounded to the nearest ten?

• 90

• 80

• 85

• 70

Tags

CCSS.3.NBT.A.1

CCSS.4.NBT.A.3

What is 50 multiplied by 80?

• 6,000

• 5,000

• 4,000

• 3,000

Tags

CCSS.4.NBT.B.5