NCERT Solutions for Class 4th Maths Chapter 4 Question 1 — Let Us Do

Book page 41 Updated on2026-09-19

Q1.
1. (a) Make 3-digit numbers using the digits 3 and 7. Write the numbers in the boxes given below. Circle the smallest and cross out the largest.
333
The eight boxes printed on page 41. One of them already shows 333.
Answer

Each of the three places can hold 3 or 7. Work place by place.

333  337  373  377
733  737  773  777

All eight numbers are made. Now compare them.

Smallest = 333 (circle it)
Largest = 777 (cross it out)
Why it happens: 3 is smaller than 7, so putting 3 in every place gives the smallest number and putting 7 in every place gives the largest.
Tip: there are exactly eight numbers because each place has two choices: 2 × 2 × 2 = 8.
Q2.
1. (b) Make six 3-digit numbers using the digits 3, 5, 0, 8 such that all numbers are less than 550. You can repeat the digits.
Answer

A 3-digit number cannot begin with 0. So the first digit must be 3 or 5.

  • If the first digit is 3, the number is in the 300s — always less than 550.
  • If the first digit is 5, the second digit must be 0 or 3, so that the number stays below 550.
Six numbers: 305, 330, 350, 380, 503, 538
NumberLess than 550?
305Yes
330Yes
350Yes
380Yes
503Yes
538Yes
Check it yourself: 553 or 580 would be wrong — they are bigger than 550. Other correct answers are possible, such as 300, 333 or 508.
Q3.
1. (c) Mark the numbers you made in 1(b) on the number line.
200250300350400450500550600
The number line printed below question 1(c).
Answer
200250300350400450500550600
The number line printed below question 1(c).

Each small step on this line is 50. Find where each number falls.

305 — just after 300
330 — between 300 and 350
350 — on the mark
380 — between 350 and 400
503 — just after 500
538 — between 500 and 550
200250300350400450500550600305330350380503538
The six numbers marked on the number line.
Why it happens: on a number line the numbers grow as we move right, so a bigger number always sits further to the right.
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