 # Dividing Decimal Numbers by 10, 100, 1000 and Multiplying by an Integer

In this worksheet, students will rehearse how to divide decimal numbers by 10, 100 and 1000. They will also practice how to multiply decimals by integers. These place value skills need to be cemented for the SATs Arithmetic paper. Key stage:  KS 2

Curriculum topic:   Exam-style Questions: SATs Maths

Curriculum subtopic:   Exam-Style Questions: Accurate Decimal Calculations

Difficulty level:   ### QUESTION 1 of 10

Great job! You have decided to spend some time practising for the SATs arithmetic test.

In this activity, you will divide decimal numbers by 10, 100 and 1000.

You will then move onto rehearsing how to multiply decimal numbers by an integer.

Example 1: Dividing by 10, 100 and 1000

Once you can multiply a decimal number by 10, 100 and 1000, you can then move onto practising how to divide by 10,100 and 1000.

Remember that 0 is always the place holder.

Also, remember that 3.4 is the same as 3.40 and 11.0 is the same as 11

When we divide a number, we move the digits to the right.

Look at the place value chart below, it shows 22.12 ÷ 10 = 2.212

Each digit has been moved one place to the right. 22.12 ÷ 10 = 2.212....All of the digits have moved one place to the right.

22.12 ÷  100 = 0.2212....All of the digits have moved two places to the right.

22.12 ÷ 1000 = 0.02212....All of the digits have moved three places to the right.

The decimal point does not move.

Example 2: Multiplying Decimals by Integers

When you multiply a decimal number by an integer, you may choose to use the column or grid method of multiplication.

Grid method: Here is the same calculation, solved using the column method: Now, over to you to try some of the practice questions...good luck!

Which direction do the digits in a number move when you divide by 10, 100 or 1000?

Left

Right

What is 44 ÷ 10?

Match each statement correctly.

## Column B

300 ÷ 10=
300
300 ÷ 100 =
0.3
300 ÷ 1000 =
3
300 ÷ 1 =
30

Choose the incorrect calculation.

2.3 x 100 = 230

2.3 x 1000 = 2300

2.3 ÷ 1000 = 0.023

2.3 ÷ 100 = 0.023

Do you agree with Simran when she says...

'It is very easy to divide by 10, 100 and 1000 because all you have to do is move the decimal point and subtract the zeros.'

Agree

Disagree

Which is bigger...

0.2     0.02     0.002?

Multiply 1.42 by 3.

Use whichever method you feel most confident with.

Calculate 1.242 x 3

Use whichever method you feel most comfortable with.

Karen bought five cans of tuna for £1.99 each.

What was the total? Train tickets cost £7.93.

If Steve, his wife and three kids go on a trip, how much will it cost them? • Question 1

Which direction do the digits in a number move when you divide by 10, 100 or 1000?

Right
EDDIE SAYS
Did you remember that all of the digits in a number move to the right when we divide? This is because dividing is the same as sharing the number and so makes the number smaller. The value of each digit is getting smaller. You've got started, now keep going!
• Question 2

What is 44 ÷ 10?

4.4
EDDIE SAYS
Nice job if you wrote 4.4. When we divide by 10, we simply move each digit one space to the right. Remember that 0 is a place holder. Division is not commutative, this means it cannot be done in any order. If we calculated 10 ÷ 44, we would get a very different answer!
• Question 3

Match each statement correctly.

## Column B

300 ÷ 10=
30
300 ÷ 100 =
3
300 ÷ 1000 =
0.3
300 ÷ 1 =
300
EDDIE SAYS
Did you read the question carefully and think about how many places to move each digit to the right? A good understanding of how to divide decimal numbers by 10, 100 and 1000 is crucial and will really help you in the SATs tests. You have made a good start- keep it up!
• Question 4

Choose the incorrect calculation.

2.3 ÷ 1000 = 0.023
EDDIE SAYS
Brilliant job if you chose 0.023; this is incorrect. 2.3 ÷ 1000 = 0.0023 Make sure you always read each question twice in the test to ensure you don't make any silly mistakes that you could easily avoid! These sorts of questions can easily trick you as they have the same digits appearing over again!
• Question 5

Do you agree with Simran when she says...

'It is very easy to divide by 10, 100 and 1000 because all you have to do is move the decimal point and subtract the zeros.'

Disagree
EDDIE SAYS
Did you notice that you should 'disagree' with Simran? Simran is wrong in her statement as the decimal point doesn't ever move, it always stays still! It is the digits that move when we divide, they move to the right, along the place value columns. This is a super effort, you are now halfway through the activity!
• Question 6

Which is bigger...

0.2     0.02     0.002?

0.2
EDDIE SAYS
Take a deep breath you've got this! Take your time and think carefully about what each digit represents. The biggest number is 0.2 0.2 represents 2 tenths, 2 tenths are bigger than 2 hundredths and 2 thousandths. If you found this one tricky, why not draw a place value chart next time to help you compare?
• Question 7

Multiply 1.42 by 3.

Use whichever method you feel most confident with.

4.26
EDDIE SAYS
Are you feeling more confident? 1.42 x 3 = 4.26 You may have chosen to use the grid or column method to solve this one. In the arithmetic test, you will be given squared paper underneath each question for your working out. Remember to put each number into its own square for accuracy.
• Question 8

Calculate 1.242 x 3

Use whichever method you feel most comfortable with.

3.726
EDDIE SAYS
Did you get the hang of this one? 1.242 x 3 = 3.726 You are making great progress...there's only 2 questions left in this activity!
• Question 9

Karen bought five cans of tuna for £1.99 each.

What was the total? EDDIE SAYS
Don't be afraid to give it a go! To crack this one, £1.99 had to be multiplied by 5, using your preferred method. With this type of question, it is a great idea to make an estimate first by rounding the decimal number. Round £1.99 up to £2. £2 x 5 =£10 This shows that our answer of £9.95 seems very sensible!
• Question 10

Train tickets cost £7.93.

If Steve, his wife and three kids go on a trip, how much will it cost them? EDDIE SAYS
Keep trying until you get it right! Hopefully, you spotted that there are 5 members of the family in total who are taking the train ride. £7.93 x 5 = £39.65 A sensible estimate would be to round £7.93 to £8 £8 x 5 = £40 This again, reassures us that our answer of £39.65 seems very sensible! Excellent work! You have completed another activity! 