Decimal Operations Review

When you multiply numbers with decimals, do you line up the decimals?

• Yes, lining up the decimals will give you the accurate answer.

• Yes, lining up the decimals makes the equation look nicer.

• No, the decimals only line up in word problems.

• No, decimals only need to be lined up for add/ subtraction equation NOT multiplication.

Answer explanation

When multiplying numbers the decimals do not need to line up. Once all your multiplication is done you will count how many decimal places you will ned to move at the end.

How many decimal places will you be moving in your final answer?

3.5 x 14.37

• 2

• 5

• 3

• 1

Answer explanation

14.37 <--- 2 decimal places

x 3.5 <--- 1 decimal place

--------

50.295 <--- 3 decimal places

3.24 ÷ 0.6 = 

• 5.25
• 0.54
• 5.4

9.08 + 14.6 = 

• 23.16
• 23.68
• 19.50
• 24.68

8.5 ⋅ 2.3 = 

• 19.55
• 195.5
• 2.95
• 20.35

While at the grocery store, Mrs. Martin noticed that there were two different sized bottles of hot sauce, one was 16.9 ounces and the other 32.55 ounces. What is the difference in weight of the two bottles of hot sauce?

WHICH OPERATION WOULD YOU USE TO SOLVE THIS PROBLEM?

• Division

• Multiplication

• Subtraction

• Addition

Billy bought 3.5 pieces of wood to build a bird feeder. Each piece of wood cost $1.50. How much did Billy spend on wood for his bird feeder?

WHICH OPERATION WOULD YOU USE TO SOLVE THIS PROBLEM?

• Division

• Multiplication

• Subtraction

• Addition

Violet stopped at 5 Guys and bought a bacon cheeseburger for $6.99, Cajun fries for $2.49, and a milkshake for $1.99. How much did Violet spend on lunch?

WHICH OPERATION WOULD YOU USE TO SOLVE THIS PROBLEM?

• Multiplication

• Division

• Subtraction

• Addition

Bill paid $32.50 for 4 fishing rods.

How much did Bill pay per fishing rod?

WHICH OPERATION WOULD YOU USE TO SOLVE THIS PROBLEM?

• Division

• Multiplication

• Subtraction

• Addition

Hummingbirds flap their wings extremely fast. Their wings can flap about 13.35 times per second. How many times would a hummingbird flap its wings in 11.15 seconds?

WHICH OPERATION WOULD YOU USE TO SOLVE THIS PROBLEM?

• Multiplication

• Division

• Subtraction

• Addition