Starter quiz
- Calculate the size of a in this representation.
- '35' ✓
- Calculate the size of a in this representation.
- 36
- 36.5
- 37
- 37.5 ✓
- 38
-
- Calculate the size of c in this representation.
- '175' ✓
- Calculate the size of e in this bar model.
- '75' ✓
- Andeep and Izzy are selling 60 ice poles. Izzy sells 8 ice poles more than Andeep. How many ice poles does Izzy sell?
- '34' ✓
- Andeep and Izzy have read 348 pages altogether. Andeep has read 32 more pages than Izzy. How many pages has Andeep read?
- '190' ✓
Exit quiz
- When the difference and sum of two unknown numbers is known, there are how many possible solutions?
- 1 ✓
- 2
- 3
- 4
- Infinite
-
- a represents a larger number. b represents a smaller number. The sum of a and b is 60, and the difference between them is 10 What number does a represent?
- 30
- 35 ✓
- 40
- 45
-
- a represents a larger numbers and b represent a smaller number. The sum of a and b is 205, and the difference between them is 25 What number does b represent?
- 80
- 85
- 90 ✓
- 95
- 100
-
- Steven is 24 years younger than his mum. The sum of their ages is 68 years. How old is Steven’s mum? ______ years old.
- '46' ✓
- The sum of two numbers is 140 One number is three times the size of the other number. What are the two numbers?
- 35 and 105 ✓
- 40 and 100
- 30 and 110
- 32 and 108
-
- The sum of two numbers is 410 One number is one-quarter times the size of the other number. What is the value of the largest number?
- '328' ✓
Worksheet
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Presentation
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Lesson Details
Key learning points
- Some problems with two unknowns have only one solution.
- If both the sum of and difference between the two unknowns are known then there will only be one solution.
- Some problems with two unknowns have many solutions.
- Some problems with two unknowns have an infinite number of solutions.
Common misconception
Pupils may draw bar models which are inaccurate and do not represent the problem effectively.
These types of problems lend themselves to be drawn using bar models that are lined up one on top of the other. Model creating these bar models with the pupils and explaining how you know where the numbers sit within them.
Keywords
Sum - The sum is the total when numbers are added together.
Difference - The difference is the result of subtracting one number from another. How much one number differs from another.
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