Starter quiz
- Two variables are inversely proportional if there is a ______ multiplicative relationship between one variable and the reciprocal of the other.
- 'constant' ✓
- Which of the following is a graph representing inverse proportion?
- Which of the following situations illustrate an inversely proportional relationship?
- The number of coaches needed for a school trip and the number of people.
- The time taken to to paint a wall and the number of people painting. ✓
- The number of pounds and the number of dollars exchanged.
- The time taken to drive to Liverpool and speed of the car. ✓
- Number of buckets needed to fill a paddling pool and the size of the buckets. ✓
-
A and B are inversely proportional. The missing value is ______.- '21' ✓
A and B are inversely proportional. The missing value is ______.- '10' ✓
- It takes 3 people 4 days to build a wall. It should take 2 people ______ days to build the same wall.
- '6' ✓
Exit quiz
- Variables which are in proportion share a __________ relationship.
- additive
- different
- multiplicative ✓
-
Here is part of a larger shape. Which of the following could be the whole shape?- If 100% = 45, 130% = 58.5 then the percentage change is ______%.
- '30' ✓
- Calculate the percentage profit on a watch bought for £40 and sold for £50.
- 125%
- 80%
- 25% ✓
- 20%
-
- Calculate the percentage loss on a mobile phone bought for £300 and sold for £240.
- 20% ✓
- 25%
- 80%
- 120%
- 125%
-
- A, B and C are 3 different numbers. C is two-fifths of B. C is 3 times A. The total of A & C is 32. The value of B is ______.
- '60' ✓
Worksheet
Loading worksheet ...
Presentation
Loading presentation ...
Video
Lesson Details
Key learning points
- Representations can support problem solving.
- Direct proportion can be used to solve real life problems.
- Inverse proportion can be used to solve real life problems.
Common misconception
Forgetting to find the percentage change.
Emphasise the word change. Encourage pupils to write down the 2 percentages with their relevant values. Go back to the question and calculate the actual change they should notice that this is neither of the 2 values but the difference between them.
Keywords
Proportion - If two things are proportional then the ratio of part to whole is maintained and the multiplicative relationship between parts is also maintained.
+