New
New
Year 2

Find 10 more or less than a 2-digit number.

I can find 10 more or 10 less than a two-digit number.

New
New
Year 2

Find 10 more or less than a 2-digit number.

I can find 10 more or 10 less than a two-digit number.

Lesson details

Key learning points

  1. When finding 10 more or 10 less than any two-digit number, the ones digits does not change.
  2. When finding 10 more than a number below 100, the tens digit increases by one.
  3. When finding 10 less than a number below 100, the tens digit decreases by one.

Common misconception

Children may default to counting in ones to find ten more or ten less.

Use representations that highlight the structure of the base 10 system, e.g. Base 10 blocks/one hundred squares, and also 'dual counting' to support understanding of 'unitising', i.e. that using 'ten' as a unit can help to calculate more efficiently.

Keywords

  • 10 more - 10 more than is when there is a greater amount by 10 than another item in the set.

  • 10 less - 10 less than is when there is a smaller value by 10

  • Increase - Make something bigger (in size or quantity).

  • Decrease - Make something smaller (in size or quantity).

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 would be used to solve this problem? Sam collected 56 pebbles and Alex collected 8 How many pebbles did they collect altogether?
Correct answer: 56 + 8 =
56 − 8 =
Q2.
Sam and Alex collected 45 shells but Alex dropped some. Now, they have 37 shells. How many did Alex drop? shells.
An image in a quiz
Correct Answer: 8, eight
Q3.
Alex and Sam collected 34 pencils in class. Sam collected 7 pencils. How many did Alex collect? pencils.
An image in a quiz
Correct Answer: 27
Q4.
Which of these equations can be solved by bridging a multiple of 10?
Correct answer: 45 + 6 =
25 + 4 =
Correct answer: 58 + 3 =
Correct answer: 68 + 5 =
Q5.
Which of these equations can be solved by bridging a multiple of 10?
44 − 2 =
Correct answer: 65 − 8 =
57 − 5 =
Correct answer: 71 − 3 =
Q6.
Which of these known facts could help you to solve this equation? 66 + 7 = ___
Correct answer: 6 + 7 = 13
Correct answer: 7 + 6 = 13
6 + 1 = 7
1 + 6 = 7

6 Questions

Q1.
Match the number of tens to the correct multiple of 10
Correct Answer:4 tens ,40

40

Correct Answer:2 tens ,20

20

Correct Answer:9 tens ,90

90

Correct Answer:5 tens ,50

50

Correct Answer:10 tens ,100

100

Q2.
Match to complete the sentence.
Correct Answer:10 more than 30 is ,40

40

Correct Answer:10 less than 60 is ,50

50

Correct Answer:10 more than 90 is ,100

100

Correct Answer:10 less than 70 is ,60

60

Q3.
Match to complete the sentence.
Correct Answer:When we count forwards in tens,,the tens digit increases by one, but the ones digit remains the same.

the tens digit increases by one, but the ones digit remains the same.

Correct Answer:When we count backwards in tens,,the tens digit decreases by one, but the ones digit remains the same.

the tens digit decreases by one, but the ones digit remains the same.

Q4.
Match so that the second number is 10 more than the first.
Correct Answer:10 more than 17 is,27

27

Correct Answer:10 more than 23 is,33

33

Correct Answer:10 more than 46 is ,56

56

Correct Answer:10 more than 65 is,75

75

Q5.
What is the missing number below?
An image in a quiz
Correct Answer: 57
Q6.
Look at the number in the place value chart. 10 less than this number is
An image in a quiz
Correct Answer: 53