New
New
Lesson 5 of 5
New
New
- Year 9
Checking a claim
I can analyse a claim using estimation to assess validity.
Lesson details
Key learning points
- Estimation can be used in place of non-specified values.
- Claims should be checked to see whether they make sense.
Keywords
Probability - The probability that an event will occur is the proportion of times the event is expected to happen in a suitably large experiment.
Estimate - To estimate is to find a value that is close enough to the right answer, usually with some thought or calculation involved.
Common misconception
Taking 20% off an amount after a percentage change will result in the original amount before 20% was added.
These are percentages of different amounts so, given that we are calculating 20% in both cases, this will not work.
This lesson could be used as an introduction to Core Maths and what Core Maths lessons are like. More information on Core Maths can be found on the AMSP website.
Teacher tip
Equipment
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.If I roll a fair 6-sided die, what is the probability that I roll a 4?
If I roll a fair 6-sided die, what is the probability that I roll a 4?
Correct answer: $$\frac{1}{6}$$
$$\frac{1}{6}$$
$$\frac{2}{6}$$
$$\frac{3}{6}$$
$$\frac{4}{6}$$
Q2.If I roll a fair 6-sided die, what is the probability that I roll a prime number?
If I roll a fair 6-sided die, what is the probability that I roll a prime number?
$$\frac{1}{6}$$
$$\frac{2}{6}$$
Correct answer: $$\frac{3}{6}$$
$$\frac{3}{6}$$
$$\frac{4}{6}$$
Q3.Alex calculates the average amount of time his classmates spend on homework in a week. Which of these might he have calculated?
Alex calculates the average amount of time his classmates spend on homework in a week. Which of these might he have calculated?
Correct answer: Mean
Mean
Correct answer: Median
Median
Correct answer: Mode
Mode
Range
Spread
Q4.Which average is found by identifying the middle value when the data is arranged in order?
Which average is found by identifying the middle value when the data is arranged in order?
Mean
Correct answer: Median
Median
Mode
Q5.In a sale, a coat is reduced by 30% and is now selling for £42. What did the coat originally cost?
In a sale, a coat is reduced by 30% and is now selling for £42. What did the coat originally cost?
Correct Answer: £60, £60.00
£60, £60.00
Q6.A painting was bought for £28 and then later sold for 34% more than it was bought for. What was it sold for?
A painting was bought for £28 and then later sold for 34% more than it was bought for. What was it sold for?
Correct Answer: £37.52
£37.52
Assessment exit quiz
6 Questions
Q1.The that an event will occur is the proportion of times the event is expected to happen in a suitably large experiment.
The that an event will occur is the proportion of times the event is expected to happen in a suitably large experiment.
Correct Answer: probability
probability
Q2.To is to find a value that is close enough to the right answer, usually with some thought or calculation involved.
To is to find a value that is close enough to the right answer, usually with some thought or calculation involved.
Correct Answer: estimate
estimate
Q3.The price of an item of clothing rose from £42 to £48. What is the percentage increase (1 d.p.) in the cost of this item?
The price of an item of clothing rose from £42 to £48. What is the percentage increase (1 d.p.) in the cost of this item?
Correct Answer: 14.3%
14.3%
Q4.The price of an item of clothing fell from £48 to £42. What is the percentage decrease (1 d.p.) in the cost of this item?
The price of an item of clothing fell from £48 to £42. What is the percentage decrease (1 d.p.) in the cost of this item?
Correct Answer: 12.5%
12.5%
Q5.In a raffle there is a 1 in 280 chance of winning a prize. What is the probability of winning if you buy one ticket? Give your answer as a percentage to 1 d.p.
In a raffle there is a 1 in 280 chance of winning a prize. What is the probability of winning if you buy one ticket? Give your answer as a percentage to 1 d.p.
Correct Answer: 0.4%
0.4%
Q6.In a raffle there is a 1 in 28 000 chance of winning a prize. Jacob thinks you can never win as the probability of winning is 0.0%. What error has Jacob made?
In a raffle there is a 1 in 28 000 chance of winning a prize. Jacob thinks you can never win as the probability of winning is 0.0%. What error has Jacob made?
Jacob is correct - you should never play as the probability of winning is 0.0%
Jacob is incorrect - the probability of winning is actually 0.00%
Correct answer: Jacob is incorrect - he has rounded to 1 d.p. so it looks like you can't win.
Jacob is incorrect - he has rounded to 1 d.p. so it looks like you can't win.
