(Lesson)Bk5C Unit 6 Problems of multiplication of decimals

Multiplication of Decimals - Solving Problems

Math Response

1 US dollars can be exchanged for 7.8 HK dollars. Fred has 15 US dollars. How many HK dollars can he exchange it for? (From an expression)

Type answer here

Correct Answer: 7.8\times15

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Math Response

20.9x2=?

Type answer here

Correct Answer: 41.8

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Math Response

Each box of deep-fried bean curd crust costs 20.9 dollars. Bella wants to buy 2 boxes, how much should she pay? (Form an expression)

Type answer here

Correct Answer: 20.9\times2

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Math Response

1 bag of pork balls weighs 0.17 kg. There are 24 bags of pork balls in one box. How many kilograms does a box of pork balls weigh? (Form an expression)

Type answer here

Correct Answer: 0.17\times24

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Math Response

0.17x24=?

Type answer here

Correct Answer: 4.08

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Multiple Choice

Dad bought 4 kg of beef. The beef cost 80 dollars for each kilogram. How

much did he pay? We can use ...... to solve this problem.

• addition

• subtraction

• multiplication

• division

Math Response

Dad bought 1.4 kg of beef. The beef cost 78.3 dollars for each kilogram. How

much did he pay? (Form an expression)

Type answer here

Correct Answer: 78.3\times1.4

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Math Response

Round off the answer of 78.4x1.4 to one decimal place.

Type answer here

Correct Answer: 109.8

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Fill in the Blanks

One can of Coca Cola is 250 mL. Ken drank one and a half cans.

Capacity of Coca Cola he drank: 250 x

Math Response

There is 0.25 L of chicken soup in each can. Mum uses 2 and a half cans for the

hotpot. How many litres of chicken soup is used altogether? (Form an expression)

Type answer here

Correct Answer: 0.25\times2.5

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Math Response

Round off the answer of 0.25x2.5 to 2 decimal places.

Type answer here

Correct Answer: 0.63

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Multiple Choice

Area of rectangle =

• ( Length + Width ) x 2

• Length + Width

• Length x Width

• Length x Width x 2

Math Response

A table cloth is 215 cm long and 98 cm wide. What is its area in m²? (Give your

answer correct to the nearest whole number.)

Type answer here

Correct Answer: 2

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