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Primary 6 Maths: Averages and Line Graphs — Practice Paper 4 (10 Questions)
Primary 6 Maths: Averages and Line Graphs — Practice Paper 4 (10 Questions)
Paper 4 puts the mean back into real data: a mean from a set, a total from a mean, then a new student or a corrected value to show how the mean moves; the middle items read a line graph for monthly sales and growth, and the last items cover two-stage average speed and the error of a total smaller than the mean.
Quick answer Ten questions, about 20 minutes. Items 01 to 03 cover a mean, a total back from a mean and a new mean after a new value joins; items 04 to 06 cover a missing value, reading a line graph and a percentage increase; items 07 to 09 cover two-stage average speed, a corrected value and the score needed next time; item 10 redoes dividing the mean again.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 questions |
| Suggested time | 20 minutes |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: Primary 6 Maths: Averages and Line Graphs — Tutor Lesson Plan |
| Level | Primary 6 |
02 Questions (10 items)
- FoundationElectricity use over four months is 68, 72, 80 and 84 units. What is the monthly average?
- FoundationThe mean of six tests is 85 marks. What is the total of the six tests?
- FoundationTwenty students have a mean mass of 60 kg. A new student of 81 kg joins. What is the new mean for 21 students?
- IntermediateFive numbers have a mean of 24. Four of them are 20, 22, 26 and 28. What is the fifth number?
- IntermediateA line graph shows 120, 150, 90 and 180 items sold from January to April. What is the monthly average?
- IntermediateFrom the same graph, how many more items were sold in April than in March, and what is the percentage increase?
- ChallengeA car averages 60 km/h for the first 3 hours and 80 km/h for the next 2 hours. What is the average speed for the whole trip?
- ChallengeSix numbers have a mean of 15. One of them, 20, is corrected to 14. What is the new mean?
- ChallengeThe first four tests average 72 marks. What is the lowest fifth score needed for a five-test mean of 74?
- Error redoFive tests have a mean of 72 marks. A student answered that the total is 14.4 marks. What is the correct total, and what went wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 76 units | The total is 68 + 72 + 80 + 84 = 304, and 304 ÷ 4 = 76 units. |
| 2 | 510 marks | Total = mean × number of items, so 85 × 6 = 510 marks. |
| 3 | 61 kg | The original total is 60 × 20 = 1 200 kg; adding 81 gives 1 281 kg, and 1 281 ÷ 21 = 61 kg. |
| 4 | 24 | The five numbers total 24 × 5 = 120; taking away the 96 of the four known numbers leaves 24. |
| 5 | 135 items | The four months total 120 + 150 + 90 + 180 = 540, and 540 ÷ 4 = 135 items. |
| 6 | 90 more items, a 100% increase | 180 − 90 = 90 items; taking March as the base, 90 ÷ 90 × 100% = 100%. |
| 7 | 68 km/h | Total distance 180 + 160 = 340 km over 5 hours gives 68 km/h; averaging 60 and 80 to 70 is wrong. |
| 8 | 14 | The total falls from 90 by 6 to 84, and 84 ÷ 6 = 14. |
| 9 | 82 marks | The first four tests total 288; five tests need 74 × 5 = 370, so 370 − 288 = 82 marks. |
| 10 | 360 marks; the mean was divided by the number of tests again | Total = mean × number = 72 × 5 = 360 marks. The 14.4 came from dividing 72 by 5, which goes the wrong way. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.
