Lesson 46 - Estimate Decimal Multiplication

Choose the best estimate by rounding to the nearest one.

37.8 x 1.6

• 760

• 76

• 660

• 66

Answer explanation

The decimal number 37.8 rounds to 38. The decimal number 1.6 rounds to 2. The estimated product is 76.

Tags

CCSS.5.NBT.B.7

Choose the best estimate by rounding to the nearest one.

14.5 x 5.5

• 70

• 700

• 900

• 90

Answer explanation

The decimal number 14.5 rounds to 15. The decimal number 5.5 rounds to 6. The estimated product is 90.

Tags

CCSS.5.NBT.B.7

Use compatible numbers to estimate the product.

40.55 x 5.6

• 246

• 245

• 200

• 240

Answer explanation

The number 40 can be easily multiplied by 6, which is what 5.5 rounds to. Multiply 4 x 6 then add a zero: 4 x 6 = 24. The estimated product is 240.

Tags

CCSS.5.NBT.B.7

Use compatible numbers to estimate the product.

72.8 x 5.7

• 42

• 420

• 45

• 450

Answer explanation

The number 70 can be easily multiplied by 6. Multiply 7 x 6 then add a zero: 7 x 6 = 42. The estimated product is 420.

Tags

CCSS.5.NBT.B.7

Dad's truck holds 16.5 gallons of gasoline. The cost of gasoline is $3.15 per gallon. About how much money will it cost Dad to fill his tank? Round to the nearest one.

• $51

• $68

• $48

• $50

Answer explanation

The decimal number 16.5 rounds to 17. The decimal amount $3.15 rounds to $3. Since 17 x 3 = 51, the estimated product is $51.

Tags

CCSS.5.NBT.B.7

Choose the best estimate by rounding to the nearest one.

5.7 x 30.30

• 15

• 150

• 18

• 180

Answer explanation

The decimal number 5.7 rounds to 6. The decimal number 30.30 rounds to 30. The estimated product is 180.

Tags

CCSS.5.NBT.B.7

Choose the best estimate by rounding to the nearest one.

60.7 x 2.3

• 122

• 120

• 180

• 183

Answer explanation

The decimal number 60.7 rounds to 61. The decimal number 2.3 rounds to 2. The estimated product is 122.

Tags

CCSS.5.NBT.B.7