Starter quiz
- Which equation would be used to solve this problem? Sam collected 56 pebbles and Alex collected 8 How many pebbles did they collect altogether?
- 56 + 8 = ✓
- 56 − 8 =
-
Sam and Alex collected 45 shells but Alex dropped some. Now, they have 37 shells. How many did Alex drop? ______ shells.- '8' ✓
Alex and Sam collected 34 pencils in class. Sam collected 7 pencils. How many did Alex collect? ______ pencils.- '27' ✓
- Which of these equations can be solved by bridging a multiple of 10?
- 45 + 6 = ✓
- 25 + 4 =
- 58 + 3 = ✓
- 68 + 5 = ✓
-
- Which of these equations can be solved by bridging a multiple of 10?
- 44 − 2 =
- 65 − 8 = ✓
- 57 − 5 =
- 71 − 3 = ✓
-
- Which of these known facts could help you to solve this equation? 66 + 7 = ___
- 6 + 7 = 13 ✓
- 7 + 6 = 13 ✓
- 6 + 1 = 7
- 1 + 6 = 7
-
Exit quiz
- Match the number of tens to the correct multiple of 10
- 4 tens⇔40 ✓
- 2 tens⇔20 ✓
- 9 tens⇔90 ✓
- 5 tens⇔50 ✓
- 10 tens⇔100 ✓
- Match to complete the sentence.
- 10 more than 30 is⇔40 ✓
- 10 less than 60 is⇔50 ✓
- 10 more than 90 is⇔100 ✓
- 10 less than 70 is⇔60 ✓
- Match to complete the sentence.
- When we count forwards in tens,⇔the tens digit increases by one, but the ones digit remains the same. ✓
- When we count backwards in tens,⇔the tens digit decreases by one, but the ones digit remains the same. ✓
- Match so that the second number is 10 more than the first.
- 10 more than 17 is⇔27 ✓
- 10 more than 23 is⇔33 ✓
- 10 more than 46 is⇔56 ✓
- 10 more than 65 is⇔75 ✓
What is the missing number below?- '57' ✓
Look at the number in the place value chart. 10 less than this number is ______- '53' ✓
Worksheet
Loading worksheet ...
Presentation
Loading presentation ...
Video
Lesson Details
Key learning points
- When finding 10 more or 10 less than any two-digit number, the ones digits does not change.
- When finding 10 more than a number below 100, the tens digit increases by one.
- 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).
+