New
New
Year 2

Add and subtract multiples of ten

I can add and subtract multiples of ten.

New
New
Year 2

Add and subtract multiples of ten

I can add and subtract multiples of ten.

Lesson details

Key learning points

  1. Unitising and known facts help you to add and subtract multiples of ten.
  2. If 3 + 2 is equal to 5 then 3 tens + 2 tens is equal to 5 tens which is equal to 50
  3. If 5 - 2 is equal to 3 then 5 tens subtract 2 tens is equal to 3 tens which is equal to 30

Common misconception

Children may not see the link between adding or subtracting ones and adding or subtracting tens. They may not know how to use known facts to help work out equations using multiples of ten.

Reinforce understanding of unitising by describing groups of objects in ones or tens. Make the link between known facts and equations using multiples of ten explicit. Show it with equipment such as base ten blocks and represent on place value charts.

Keywords

  • Add - To find the total, or sum, by combining two or more parts (addends), or to increase an amount by adding another.

  • Subtract - To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away.

  • Multiple of ten - A multiple of 10 is a number which can be made of groups of ten.

Unitising and using known facts helps develop relational reasoning, enabling us to work with numbers in more efficient and flexible ways, relying less on counting. Seeing these in a range of contexts will help to apply them in other contexts. Represent these on bar models and place value charts.
Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which equation is being represented?
An image in a quiz
Correct answer: 6 tens subtract 4 tens =
6 tens add 4 tens =
6 tens subtract 2 tens =
Q2.
Match the statements.
Correct Answer:I know that 5 plus 4 is equal to 9,so 5 tens plus 4 tens is equal to 9 tens.

so 5 tens plus 4 tens is equal to 9 tens.

Correct Answer:I know that 1 plus 5 is equal to 6,so 1 ten plus 5 tens is equal to 6 tens.

so 1 ten plus 5 tens is equal to 6 tens.

Correct Answer:I know that 2 plus 3 is equal to 5,so 2 tens plus 3 tens is equal to 5 tens.

so 2 tens plus 3 tens is equal to 5 tens.

Q3.
Complete the equation. 7 tens = 1 tens + tens
Correct Answer: 6, six
Q4.
Complete the equation. { }} tens + 3 tens = 5 tens
Correct Answer: 2, two
Q5.
Alex says, “I know that 9 minus 6 is equal to 3”. Which of the following equations would Alex’s statement help to solve?
9 tens add 6 tens =
6 tens subtract 3 tens =
Correct answer: 9 tens subtract 6 tens =
Q6.
Order the equations starting with the greatest.
1 - 3 tens + 6 tens =
2 - 1 ten + 3 tens =
3 - 2 tens + 1 ten =

6 Questions

Q1.
Aisha shows an answer on a place value chart. Which equation could she have been answering?
An image in a quiz
70 − 10 =
Correct answer: 30 + 40 =
60 + 20 =
Correct answer: 90 − 20 =
Q2.
Match the expressions that have the same answer.
Correct Answer:10 + 30 ,20 + 20

20 + 20

Correct Answer:60 − 50 ,30 − 20

30 − 20

Correct Answer:30 + 20 ,90 − 40

90 − 40

Q3.
Match the expressions that have the same answer.
Correct Answer:10 + 60 ,50 + 20

50 + 20

Correct Answer:80 − 60 ,10 + 10

10 + 10

Correct Answer:60 − 30 ,70 − 40

70 − 40

Q4.
What is the missing part in this part-part-whole model?
An image in a quiz
10
Correct answer: 40
50
60
Q5.
What is the missing part in this bar model?
An image in a quiz
Correct answer: 20
50
70
90
Q6.
What is the missing part in this equation? 70 − = 10
10
Correct answer: 60
70
80

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