New
New
Year 2

Add and subtract 10 to and from a 2-digit number.

I can add and subtract 10 to and from a two-digit number.

New
New
Year 2

Add and subtract 10 to and from a 2-digit number.

I can add and subtract 10 to and from a two-digit number.

Lesson details

Key learning points

  1. When adding or subtracting 10, the ones digits does not change.
  2. When adding 10, the tens digit increases by one; when subtracting 10, the tens digit decreases by one.
  3. When numbers have the same ones digit and the tens digit has a difference of one, they will have a difference of 10
  4. Understanding the patterns when we add and subtract 10 can help us solve equations efficiently.

Common misconception

Children may focus on the ones digit rather than the tens digits. They may calculate inefficiently by counting on/back in ones rather than using the pattern in the tens digits.

Use Base 10 equipment alongside one hundred squares to support with understanding the structure of adding or subtracting ten and difference. Encourage children to notice what changes and what stays the same.

Keywords

  • Efficiently - Not wasting time or effort. An efficient strategy is one we can carry out easily.

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.
Match to complete the sentence.
Correct Answer:10 more than 50 is,60

60

Correct Answer:10 less than 100 is ,90

90

Correct Answer:10 more than 60 is,70

70

Correct Answer:10 less than 30 is,20

20

Q2.
True or false. The numbers in this sequence are increasing by 10 each time.
An image in a quiz
True
Correct answer: False
Q3.
Match so that the second number is 10 more than the first.
Correct Answer:10 more than 28 is,38

38

Correct Answer:10 more than 41 is ,51

51

Correct Answer:10 more than 69 is,79

79

Correct Answer:10 more than 82 is,92

92

Q4.
Match so that the second number is 10 less than the first.
Correct Answer:10 less than 33 is,23

23

Correct Answer:10 less than 42 is,32

32

Correct Answer:10 less than 56 is,46

46

Correct Answer:10 less than 71 is,61

61

Q5.
What is the missing number below?
An image in a quiz
Correct Answer: 69
Q6.
Look at the number in the place value chart. 10 less than this number is
An image in a quiz
Correct Answer: 84

6 Questions

Q1.
Adding 10 is the same as finding 10 more. Match the equations to their sums.
Correct Answer:34 + 10 =,44

44

Correct Answer:57 + 10 =,67

67

Correct Answer:61 + 10 =,71

71

Correct Answer:88 + 10 =,98

98

Q2.
Subtracting 10 is the same as finding 10 less. Match the equations to their difference.
Correct Answer:35 − 10 = ,25

25

Correct Answer:49 − 10 = ,39

39

Correct Answer:62 − 10 = ,52

52

Correct Answer:97 − 10 = ,87

87

Q3.
10 + 72 =
Correct Answer: 82
Q4.
89 − 10 =
Correct Answer: 79
Q5.
Match two numbers that have a difference of 10
Correct Answer:55,45

45

Correct Answer:44,54

54

Correct Answer:61,71

71

Correct Answer:17,27

27

Q6.
54 and ___ have a difference of 10
Correct answer: 44
55
Correct answer: 64
45