Primary 5 Mathematics Multiplication Division Quiz

Primary 5 Mathematics Quiz - Multiplication Division (Answer Key)

Total Marks: 40
Topic: Multiplication and Division (syllabus-first, no past-year evidence claimed)

Section A Answers (Q1–10, 2 marks each)

Q1. $248 \times 36 = 8928$
Working: $248 \times 30 = 7440$; $248 \times 6 = 1488$; $7440 + 1488 = 8928$.
Teaching note: Break 36 into 30 and 6 (expanded form). Multiply then add. Common mistake: misalignment of place values.

Q2. $6720 \div 24 = 280$
Working: $24 \times 200 = 4800$, remainder $1920$; $24 \times 80 = 1920$; $200+80=280$.
Teaching note: Use long division or chunking. Check: $280 \times 24 = 6720$.

Q3. $15 \times 28 = 420$ sweets
Working: $10 \times 28 = 280$, $5 \times 28 = 140$, $280+140=420$.
Teaching note: Total = packets × sweets per packet.

Q4. $936 \div 26 = 36$ pupils
Working: $26 \times 30 = 780$, remainder 156; $26 \times 6 = 156$; $30+6=36$.
Teaching note: Equal sharing → division.

Q5. $3.6 \times 100 = 360$
Teaching note: Multiplying by 100 moves decimal point 2 places right.

Q6. $48.5 \div 10 = 4.85$
Teaching note: Dividing by 10 moves decimal point 1 place left.

Q7. $\frac{2}{3} \times 18 = 12$
Working: $18 \div 3 = 6$, $6 \times 2 = 12$.
Teaching note: Fraction of a whole number = divide by denominator, multiply by numerator.

Q8. $\frac{5}{8} \times \frac{4}{5} = \frac{1}{2}$
Working: $\frac{5 \times 4}{8 \times 5} = \frac{20}{40} = \frac{1}{2}$ (or cancel 5 and 4 with 8: $\frac{1}{2} \times \frac{1}{1} = \frac{1}{2}$).
Teaching note: Multiply numerators, multiply denominators, simplify.

Q9. $444 \div 12 = 37$ trays
Working: $12 \times 37 = 444$.
Teaching note: Number of groups = total ÷ per group.

Q10. $125 \times 40 = 5000$
Working: $125 \times 4 = 500$, $500 \times 10 = 5000$.
Teaching note: $40 = 4 \times 10$.

Section B Answers (Q11–16, 3 marks each)

Q11. (a) $24 \div 8 =$3$(1 mark) (b)$3 \times 35 = $105$ (2 marks)
Teaching note: Unit rate first, then scale up.

Q12. (a) $2.5 \ell = 2500$ ml (1 mark: $2.5 \times 1000$) (b) $2500 \div 5 = 500$ ml (2 marks)
Teaching note: $1 \ell = 1000$ ml.

Q13. $1\frac{1}{2} \times \frac{3}{4} = \frac{3}{2} \times \frac{3}{4} = \frac{9}{8} = 1\frac{1}{8}$ (3 marks: convert mixed no. 1, multiply 1, simplify 1)
Teaching note: Change mixed number to improper fraction before multiplying.

Q14. Buses used: $18 \times \frac{5}{6} = 15$ (1 mark). Passengers: $15 \times 54 = 810$ (2 marks).
Teaching note: Fraction of a whole number then multiply.

Q15. $8.4 \div 0.7 = 12$ (3 marks)
Working: $8.4 \div 0.7 = 84 \div 7 = 12$.
Teaching note: Multiply both by 10 to make divisor whole.

Q16. (a) $36 \div 2.25 = 16$ curtains (2 marks: $36 \div 2.25 = 3600 \div 225 = 16$) (b) $36 - (16 \times 2.25) = 36 - 36 = 0$ m left (1 mark)
Teaching note: Full curtains only → whole number quotient.

Section C Answers (Q17–20, 4 marks each)

Q17. Book: $\frac{1}{3} \times 120 =$40$(1 mark). Remainder:$120 - 40 = $80$ (1 mark). Pen: $\frac{1}{4} \times 80 =$20$(1 mark). Left:$80 - 20 = $60$ (1 mark).
Answer: $60. Teaching note: Fraction of remainder changes the base amount.

Q18. Per day: $245 \times 8 = 1960$ (2 marks). Per week: $1960 \times 6 = 11760$ (2 marks).
Answer: 11760 toy cars. Teaching note: Two-step multiplication (rate × time × days).

Q19. (a) $6 \div \frac{3}{4} = 6 \times \frac{4}{3} = 8$ cakes (2 marks). (b) $8 \times 5 =$40$ (2 marks).
Teaching note: Dividing by fraction = multiply by reciprocal.

Q20. First part: $60 \times 2.5 = 150$ km (2 marks). Second: $45 \times 1.5 = 67.5$ km (1 mark). Total: $150 + 67.5 = 217.5$ km (1 mark).
Answer: 217.5 km. Teaching note: Distance = speed × time for each segment.