Decimals (Math 4)

Decimals (Math 4)

Chapter 8 (page 80)

Simple Addition

Min needs to use 1.2 kg of sugar and 3.6 kg of flour to bake a cake. How much sugar and flour does she need altogether?

Multiple Choice

How much sugar and flour does Min need altogether?

• 4.8

• 5.8

• 3.9

• 2.4

Fill in the Blanks

Addition with regrouping

The length of an eraser is 3.4cm. The length of a paper clip is 5.6cm. What is the total length of the eraser and the paper clip?

Multiple Choice

What is the total length of the eraser and the paper clip?

• 9

• 8.00

• 8.10

• 9.10

When we add the tenths and get more than 9 tenths, we regroup the lengths into ones and tenths.

When we add the hundredths and get more than 9 hundredths, we regroup the hundredths into tenths and hundredths.

Simple Subtraction

Rita's mass is 35.2 kg. Smarty's mass is 48.9 kg. How much heavier is Smarty than Rita?

Check whether the answer is reasonable.

Multiple Choice

How much heavier is Smarty than Rita?

• 73.1

• 1.37

• 13.7

• 7.31

Subtraction with regrouping

Ari wants to buy a toy helicopter which costs $87.20. He only has $61.95. How much more money does Ari need?

Number patterns

What number is 0.1 more than 3.6?

What number is 0.1 less than 3.6?

Multiple Choice

What number is 0.01 more than 10.67?

• 10.66

• 10.68

Multiple Choice

What number is 0.01 less than 10.67?

• 10.77

• 10.68

• 10.57

• 10.66

Look at the following number pattern.

What is the missing number?

Fill in the Blanks

Multiple Choice

Find the missing number in the number pattern below.

3.77, 3.74, 3.71, ___, 3.65

• 3.68

• 3.69

• 3.70

• 3.67

Rounding decimals

Nearest whole number

The length of a caterpillar is 8.3cm. Round its length to the nearest centimeter.

Fill in the Blanks

Multiple Choice

Tom's mass is 34.6 kg. Round his mass to the nearest kilogram.

• 34 kg

• 35 kg

• 34.5 kg

• 34.7 kg

Multiple Choice

A toy train costs $49.71. Round this amount to the nearest dollar.

• $50

• $49

When we round a number to the nearest whole number, we look at the digit in the tenths place.

• if the digit < 5, we round it to the smaller whole number.

• if the digit > 5, we round it to the bigger whole number.

• if the digit = 5, we round it to the bigger whole number.

Nearest tenth

A music box has a mass of 3.95 kg. Round its mass to the nearest tenth.

Multiple Choice

A music box has a mass of 3.95 kg. Round its mass to the nearest tenth.

• 3.9 kg

• 4.0 kg

Multiple Choice

A vase has a capacity of 0.72 L. Round its capacity to the nearest tenth.

• 0.8 L

• 0.7 L

When we round a number to the nearest tenth, we look at the digit in the hundredths place.

• if the digit < 5, we round it to the smaller tenth.

• if the digit > 5, we round it to the bigger tenth.

• if the digit = 5, we round it to the bigger tenth.

Multiplication

Multiplication by one-digit numbers

Min has 6 ribbons. The length of each ribbon is 1.1m. What is the total length of the ribbons Min has?

Multiple Choice

Find the product of 4 and 43.6.

• 174.4

• 17.44

• 162.24

• 1612.4

Multiple Choice

The mass of a stuffed toy is 30.4g. The mass of a toy airplane is double the mass of the stuffed toy. What is the mass of the toy airplane?

• 68g

• 60.8g

• 60.4g

• 62g

Multiplication by 10, 100 and 1000

What is 0.1 x 10?

What is 0.01 x 100

When a decimal is multiplied by 10, the digits move 1 place to the left to give the product.

When a decimal is multiplied by 100, the digits move 2 places to the left to give the product.

When a decimal is multiplied by 1000, the digits move 3 places to the left to give the product.

Division

Division by one-digit numbers

A barrel contains 9.6L of water. It can fill exactly 4 bottles. How much water can each bottle hold?

Multiple Choice

Each bottle can hold ____ of water.

• 21L

• 24L

• 2.1L

• 2.4L

Multiple Choice

The length of a bread stick is 41.7cm. Min cuts it into 3 equal pieces. What is the length of each piece of bread stick?

• 139

• 1.39

• 13.9

• 1390

Multiple Choice

Find the quotient of 8.5 divided by 6. Round your answer to 1 decimal place.

• 1.1

• 1.4

• 1.2

• 1.5

Multiple Choice

The height of an adult giraffe is 6.6m. A young giraffe is half as tall as the adult giraffe. What is the height of the young giraffe?

• 1.5

• 12.12

• 13.2

• 3.3

Let us now divide 2 by 8.

Division by 10, 100 and 1000

Divide 25 by 10

When a decimal is divided by 10, the digits move 1 place to the right to give the quotient.

When a decimal is divided by 100, the digits move 2 places to the right to give the quotient.

When a decimal is divided by 1000, the digits move 3 places to the right to give the quotient.

Fractions and decimals

Converting fractions into decimals

We can convert fractions into decimals by converting them into equivalent fractions with denominators of 10 or 100.

Multiple Choice

Express  $\frac{1}{20}$   as a decimal.

• 0.05

• 0.5

• 0.2

• 0.02

Multiple Choice

Express  $\frac{3}{5}$   as a decimal.

• 0.06

• 0.6

• 0.4

• 0.04

We can convert fractions and mixed numbers into decimals using division.

Multiple Choice

Express  $\frac{2}{7}$  as a decimal. Round the answer to 1 decimal place.

• 0.2

• 0.3

Multiple Choice

Let us now express  $\frac{11}{3}$  as a decimal. Round the answer to 1 decimal place.

• 3.7

• 3.6
  

Multiple Choice

What is $2\frac{5}{9}$  as a decimal? Round the answer to 1 decimal place.

• 2.6
  

• 2.5
  

Converting decimals into fractions

Express 0.4 as a fraction in its simplest form.

Multiple Choice

Express 6.75 as a fraction in its simplest form.

• 
  $6\frac{3}{4}$

• $6\frac{3}{5}$

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