NCERT Solutions for Class 4th Maths Chapter 8 Mr Krishna’s perfumed oil — Let Us Do

Book page 125 Updated on2026-09-19

Q1.
Mr Krishna packages perfumed oils in different sized bottles. During a festival, the following customers asked for 1 l perfumed oils but in different sized bottles. Write the number of bottles each of them will get. a) Ms Shetty wants bottles of 500 ml each b) Mr Muthukumar wants bottles of 200 ml each c) Ms Naini wants bottles of 100 ml each d) Ms Kannan wants bottles of 50 ml each
Answer

Every customer gets 1 l, and 1 l = 1000 ml. So each time we ask: how many of these small bottles make 1000 ml?

CustomerBottle sizeCountingBottles
a) Ms Shetty500 ml500, 10002
b) Mr Muthukumar200 ml200, 400, 600, 800, 10005
c) Ms Naini100 ml100, 200, 300, 400, 500, 600, 700, 800, 900, 100010
d) Ms Kannan50 mltwo 50 ml make 100 ml, and 1000 ml has ten 100 ml → 10 × 220

a) 2   b) 5   c) 10   d) 20

Why it happens: The oil is the same 1000 ml every time. Smaller bottles hold less, so more bottles are needed to hold the same oil.
Tip: Check each answer by adding back: 5 × 200 ml = 1000 ml, 20 × 50 ml = 1000 ml.
Q2.
Estimate and verify by measuring. Use the bottles you have collected for this purpose (for example, 500 ml, 250 ml, 100 ml, 50 ml, and 10 ml).
ContainerEstimateActual capacity
Water bottle  
Glass  
Mug  
Jug  
Bucket  
Teaspoon  
Bowl  
Answer

This is the table printed in the book:

ContainerEstimateActual capacity
Water bottle  
Glass  
Mug  
Jug  
Bucket  
Teaspoon  
Bowl  

First write your guess in the ‘Estimate’ column. Then fill the container with a measuring bottle and write the real answer.

Sample answer (your containers may be bigger or smaller):

ContainerEstimateActual capacity
Water bottle1 l1 l
Glass200 ml250 ml
Mug250 ml300 ml
Jug2 l2 l
Bucket10 l15 l
Teaspoon5 ml5 ml
Bowl250 ml200 ml
Why it happens: Estimating first and measuring afterwards trains the eye. Soon you will be able to look at a mug and say ‘about 300 ml’ without pouring at all.
Tip: The last two rows in the book’s table are empty. Add two containers of your own choice, such as a lota or a lunch-box.
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