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Primary 4 Maths: Adding and Subtracting Fractions | 10 Challenge Items
Primary 4 Maths: Adding and Subtracting Fractions | 10 Challenge Items
Ten items combine and reverse the skills: three-term chains, brackets first, finding the original number, comparing with one, and the remainder after two cuts or two stages.
Reverse and compare Challenge items ask for judgement, not just arithmetic. Reverse items undo an addition with a subtraction; comparison items compute first and then subtract from one; remainder items subtract twice, keeping the common denominator to the end.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 25 |
| Difficulty mix | Challenge 10 |
| Chapter | Chapter: Primary 4 Maths: Adding and Subtracting Fractions |
| Level | Primary 4 |
02 Questions (10 items)
- ChallengeWork out 2/3 + 5/6 + 3/4.
- ChallengeWork out 5 1/4 − (2 1/3 + 1 5/6).
- ChallengeWork out 7/8 + 5/6 − 3/4.
- ChallengeA number plus 2 3/5 gives 6 1/2. Find the number.
- ChallengeBy how much is 3/4 + 1/8 short of 1?
- ChallengeA bucket holds 3 1/2 L. After 4/5 L and then 1 1/4 L are used, how much is left?
- ChallengeA cloth is 4 2/3 m long. After 1 5/6 m and then 7/8 m are cut off, how much remains?
- ChallengeFraction A is 5/6 − 1/4 and fraction B is 2/3 − 1/6. Find A + B.
- ChallengeEach cup holds 5/8 L. After three full cups and another 3/4 L, what is the total?
- ChallengeA route is 9/10 km. After 2/5 km and then 1/8 km, how much is left?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | The answer is 27/12, that is 2 1/4. | The common denominator is 12: 8/12 plus 10/12 plus 9/12 gives 27/12. |
| 2 | The answer is 13/12, that is 1 1/12. | Add inside the brackets to get 25/6, then subtract from 21/4 to get 13/12. |
| 3 | The answer is 23/24. | The common denominator is 24: 21/24 plus 20/24 minus 18/24 gives 23/24. |
| 4 | The answer is 39/10, that is 3 9/10. | Work backwards: 13/2 minus 13/5 gives 39/10. |
| 5 | It is short by 1/8. | 3/4 plus 1/8 gives 7/8, and 1 minus 7/8 is 1/8. |
| 6 | The answer is 29/20 L, that is 1 9/20 L. | With 20 as denominator: 70 − 16 − 25 = 29, so 29/20 L. |
| 7 | The answer is 47/24 m, that is 1 23/24 m. | With 24 as denominator: 112 − 44 − 21 = 47, so 47/24 m. |
| 8 | The answer is 13/12, that is 1 1/12. | A is 7/12 and B is 1/2, so A plus B gives 13/12. |
| 9 | The answer is 21/8 L, that is 2 5/8 L. | Three cups give 15/8 L, and adding 6/8 L gives 21/8 L. |
| 10 | The answer is 15/40 km, that is 3/8 km. | With 40 as denominator: 36 − 16 − 5 = 15, which simplifies to 3/8. |
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.
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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.