Everything you need to ace this chapter, in one place.
Notes · Mind Map · Quiz · Assertion-Reason · Case Studies · Question Bank · Past Papers
Q1. Aaron walks 3 km in 1 hour. How far does he walk in 2 hours?
Answer: A — Walking is repeated equally, so multiply hours by distance per hour: 2 × 3 = 6 km.
Q2. A tortoise walks 1/4 km in 1 hour. How far in 3 hours?
Answer: A — Multiply 3 × 1/4 = 3/4 km (repeat the fraction three times).
Q3. What is 1/2 × 1/4 using the unit square method?
Answer: B — Dividing into 2 rows and 4 columns creates 8 parts; one part shaded = 1/8.
Q4. To multiply fractions 5/12 × 7/18, what do you compute?
Answer: B — Multiply numerators together and denominators together: (5 × 7)/(12 × 18) = 35/216.
Q5. A farmer gives 2/3 acre to each of 5 grandchildren. Total land given?
Answer: A — 5 grandchildren each get 2/3 acre, so multiply: 5 × 2/3 = 10/3 or 3 1/3 acres.
Q6. Internet time costs ₹8 per hour. Cost for 1 1/4 hours?
Answer: C — 1 1/4 = 5/4 hours; 5/4 × 8 = (5 × 8)/4 = 40/4 = ₹10.
Q7. When multiplying 12/7 × 5/24, you can cancel 12 and 24 because?
Answer: B — Common factors can be divided out before multiplying to simplify: 12/24 = 1/2, giving 1 × 5/(7 × 2) = 5/14.
Q8. Manju's team can build 1 km of canal in 8 days. In 1 day, they build?
Answer: B — Divide the work equally: 1 km ÷ 8 days = 1/8 km per day (or 1 × 1/8).
Q9. The Moon sets 5/6 hour later each day. After 4 days from Monday 10 pm, when does it set on Friday?
Answer: A — Multiply days by delay: 4 × 5/6 = 20/6 = 3 1/3 hours delay from Monday 10 pm.
Q10. What must you do before multiplying 14/15 × 25/42 to make it easier?
Answer: C — Cancelling reduces large numbers: 14÷7=2, 42÷7=6, 25÷5=5, 15÷5=3, leaving (2×5)/(6×3)=5/9 instead of 350/630.
What is 3 × 1/4 in km if tortoise walks 1/4 km per hour?
3 × 1/4 = 3/4 km (add the fraction three times: 1/4 + 1/4 + 1/4).
How do you multiply two fractions like 3/4 × 2/5?
Multiply numerators together and denominators together: (3 × 2)/(4 × 5) = 6/20 = 3/10.
Why can you cancel 12 and 24 before multiplying 12/7 × 5/24?
Both 12 and 24 share a common factor of 12, so dividing both by 12 simplifies to 1 × 5/(7 × 2) = 5/14 without large numbers.
What does the unit square represent in fraction multiplication?
The unit square represents 1 whole, and dividing it into rows and columns shows how fractions of fractions create smaller pieces.
If 1 hour costs ₹8, how much does 1 1/4 hours cost using multiplication?
Convert 1 1/4 to 5/4 hours, then 5/4 × 8 = (5 × 8)/4 = 40/4 = ₹10.
What is 1/2 × 1/4 using the unit square method?
Divide the unit square into 2 rows and 4 columns (8 parts total), shade 1 part: 1/2 × 1/4 = 1/8.
How do you convert a whole number to a fraction for multiplication?
Write the whole number as a fraction with denominator 1, e.g., 3 = 3/1, then multiply using the fraction rule.
What is 14/15 × 25/42 after cancelling common factors?
Cancel 14 with 42 (÷7) and 25 with 15 (÷5): (1 × 5)/(3 × 3) = 5/9.
If Tenzin drinks 1/2 glass of milk daily, how much in 7 days?
7 × 1/2 = 7/2 = 3 1/2 glasses (add 1/2 seven times or multiply 7 by numerator, keep denominator).
What is the area of a rectangle with sides 1/2 unit and 1/4 unit?
Area = length × breadth = 1/2 × 1/4 = 1/8 square unit (shown by 1 shaded rectangle out of 8 in unit square).
Tenzin drinks 1/2 glass of milk every day. How many glasses does he drink in one week? [1 mark]
Multiply 7 days by 1/2 glass per day using the rule: whole number × fraction = (whole × numerator) ÷ denominator.
A water tap fills 7/10 of a tank in 1 hour. How much of the tank is filled in 3/4 hour? Show your working. [2 marks]
Use the formula fraction × fraction: (3/4) × (7/10) = (3×7)/(4×10). Simplify if needed before multiplying.
A farmer distributes 2/3 acre of land to each of her 5 grandchildren. How much total land does she give? Convert your answer to a mixed fraction and explain using the multiplication rule for fraction × whole number. [3 marks]
Multiply 5 × 2/3 = (5×2)/3 = 10/3. Convert improper fraction to mixed fraction: 10÷3 = 3 remainder 1, so 3 1/3 acres.
The government took 1/6 of Somu's land for a road. Of the remaining land, she gives half to her daughter Krishna. (a) What fraction of the original land remains after the road? (b) What fraction does Krishna receive? (c) Draw a unit square to show all divisions. Show all steps clearly. [5 marks]
Step 1: Find remaining land = 1 - 1/6 = 5/6. Step 2: Krishna gets half of remaining = 1/2 × 5/6 = 5/12 (multiply numerators and denominators). Step 3: Use unit square divided into 6 rows; shade 5 parts for remaining land, then divide those 5 parts in half (creating 12 total parts).
Q1. Assertion (A):
When a fraction is multiplied by a whole number, we multiply the whole number by the numerator and keep the denominator unchanged.
Reason (R):
Multiplying a fraction by a whole number means repeating the fraction that many times, so the denominator remains the number of equal parts in the original fraction.
Answer: A — Both A and R are true, and R is the correct explanation of A — Both the assertion and reason are true. When we calculate 5 × 2/3, we are adding 2/3 five times, which gives (5 × 2)/3 = 10/3. The denominator stays as 3 because we're still dividing into thirds. The reason correctly explains why the denominator doesn't change.
Q2. Assertion (A):
The product 2/3 × 4/5 can be found by multiplying numerators and denominators separately: (2 × 4)/(3 × 5) = 8/15.
Reason (R):
This method works because it represents the area of a rectangle with sides 2/3 and 4/5 units.
Answer: B — Both A and R are true, but R is NOT the correct explanation of A — The assertion is correct: 2/3 × 4/5 = 8/15. However, the reason is not the complete or most fundamental explanation. While the area model does illustrate this multiplication, the reason is not why the rule works—the rule comes from the definition of fraction multiplication and the distributive property. Both statements are true, but the reason doesn't correctly explain the assertion.
Q3. Assertion (A):
To find 1/2 hour's distance when 1 hour distance is 3 km, we calculate 1/2 × 3 = 3/2 km.
Reason (R):
The distance is proportional to time, so multiplying 1/2 by the hourly distance gives the distance for half an hour.
Answer: A — Both A and R are true, and R is the correct explanation of A — Both the assertion and reason are correct. If 3 km is covered in 1 hour, then in 1/2 hour, the distance is 1/2 × 3 = 3/2 km. The reason (proportionality) correctly explains why we perform this multiplication operation.
Unlock more Assertion-Reason questions in Premium — unlock →
Case Study:
Priya is preparing snacks for a school event. She has a recipe that calls for 2/3 cup of sugar to make one batch of cookies. She needs to make 5 batches for the event. Additionally, her friend Rahul asks her to make 3/4 of a batch for his sister's birthday. After calculating the sugar needed, Priya realizes she should also prepare a special dessert that requires 1/2 of the sugar she originally calculated for the 5 batches.
Q1. How much sugar does Priya need for 5 batches of cookies?
Answer: A
Q2. How much sugar is needed for Rahul's 3/4 batch?
Answer: B
Q3. How much sugar is needed for the special dessert (which is 1/2 of the sugar for 5 batches)?
Answer: D
Q4. What is the total sugar needed for all three items (5 batches + 3/4 batch + dessert)?
Answer: D
Unlock more case studies in Premium — unlock →
You've seen the free preview. Open the full interactive study kit — mind map, instant-graded quiz, progress tracking — free, no sign-in required.
Open Full Study Kit — Free →Premium unlocks the full Question Bank, Daily Practice Papers, Chapter Quiz and Full Mock Papers for every chapter.