Foundation June 2022 Paper 2 Q12
12 Dinosaurs first appeared on Earth \(2.4 \times 10^8\) years ago.
Dinosaurs became extinct on Earth \(7 \times 10^7\) years ago.
(a) Explain why it is appropriate to use standard form for these numbers. [1]
(b) Use the given information to work out how long dinosaurs existed on Earth.
Give your answer in standard form. [3]
Give your answer in standard form. [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| Correct comment about large numbers or too many zeros oe | 1 | e.g. Standard form is used for [very] large/long numbers [or very small numbers] Writing out all the zeros may lead to errors See Appendix | |
Appendix
Exemplar responses for Question 12a
| Response | Mark | |
|---|---|---|
| 1 | Writing all the 0’s out is very long/difficult to read/may lead to errors | 1 |
| 2 | As they contain a lot of 0s | 1 |
| 3 | Because there are too many zeros | 1 |
| 4 | Because the numbers are extremely long/high/large, shortening the number. | 1 |
| 5 | Because of how long/high/large the number will be | 1 |
| 6 | The numbers are too long to write down e.g. \(7 \times 10^7 = 70\,000\,000\) | 1 |
| 7 | It shortens the numbers due to them having so many 0s | 1 |
| 8 | Because they’re too big (Given the wording of the demand – refers to numbers) | 1 |
| 9 | It takes too long to write it all out | 1 |
| 10 | Because the digits will be too long (BOD infers numbers are too long) | BOD 1 |
| 11 | Wastes time writing out the digits, this is simple shorthand (similar to above) | BOD 1 |
| 12 | To makes it easier to read (no reason given as to why) | 0 |
| 13 | To make the numbers more simpler (no reason given e.g. numbers too large, too many zeros) | 0 |
| 14 | Its easier to understand (no reason given as to why) | 0 |
| 15 | Because otherwise you need to write 2.4 billion years ago so \(2.4 \times 10^8\) is easier to say in standard form (Contains error in number, if 240 million years this would be OK) | 0 |
| 16 | Because the numbers are billions so it’s easier to read them in standard form (see above) | 0 |
| 17 | It shortens the numbers (no reason given why e.g. too large, too many zeros) | 0 |
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| \(1.7 \times 10^8\) | 3 | M2 for figs 17 in final answer or B1 for 240 000 000 or 70 000 000 or \(24 \times 10^7\) or \(0.7 \times 10^8\) or M1 for \(2.4 \times 10^8 - 7 \times 10^7\) oe | Accept both converted to same power of 10 e.g. \(240 \times 10^6\) and \(70 \times 10^6\) For M1, if standard form subtraction written correctly, isw incorrect conversion to values |