EN हिं

NCERT Solutions for Class 4th Maths Chapter 4 Question 2 · Fill in the blanks — Let Us Do

Book page 42 Updated on2026-09-19

Q1.
2. Fill in the blanks with appropriate numbers. (a) The caterpillar: 787, 788, …
Answer
787788
The caterpillar has 20 rings. Only the first two carry numbers.

787 and 788 are next to each other, so the rings count on one at a time.

787, 788, 789, 790, 791, 792, 793, 794, 795, 796,
797, 798, 799, 800, 801, 802, 803, 804, 805, 806
787788789790791792793794795796797798799800801802803804805806
All 20 rings filled in.
Why it happens: after 799 the ones and the tens are both full, so both become 0 and the hundreds digit goes up by one — that gives 800.
Q2.
2. Fill in the blanks with appropriate numbers. (b) The train.
Answer
The train has an engine and 10 coaches. No number is printed on it.

Note about the book: no number is printed on any coach of this train, so you may start from any number you like and keep counting on by one.

Sample answer:
995, 996, 997, 998, 999, 1000, 1001, 1002, 1003, 1004
99599699799899910001001100210031004
Sample answer: ten numbers in order.
Why it happens: after 999 all three places are full. They all turn to 0 and a new Thousands place opens, so the next number is 1000.
Try This: start from 2497 instead and fill the ten coaches again.
Q3.
2. Fill in the blanks with appropriate numbers. (c) The pumpkins on the vine: 679 and 689 are given.
Answer
679689
Ten pumpkins hang on the vine. Two carry numbers.

679 and 689 are on pumpkins that stand next to each other.

689 – 679 = 10
So the count goes up by 10 each time.
629, 639, 649, 659, 669, 679, 689, 699, 709, 719
629639649659669679689699709719
All ten pumpkins filled in.
Why it happens: adding 10 changes only the Tens digit, so the ones digit stays 9 all the way along the vine.
Q4.
2. Fill in the blanks with appropriate numbers. (d) The cars: 338 is on the 2nd car and 348 is on the 4th car.
Answer
338348
Ten cars in a row. The 2nd and the 4th carry numbers.
From the 2nd car to the 4th car is 2 steps.
348 – 338 = 10
10 shared over 2 steps → each step is 5
333, 338, 343, 348, 353, 358, 363, 368, 373, 378
333338343348353358363368373378
All ten cars filled in.
Why it happens: this is skip-counting by 5. The ones digit keeps turning 3, 8, 3, 8 — a useful check.
Q5.
2. Fill in the blanks with appropriate numbers. (e) The fish: 367 is on the 3rd fish and 567 is on the 5th fish.
Answer
367567
Ten fish in the water. The 3rd and the 5th carry numbers.
From the 3rd fish to the 5th fish is 2 steps.
567 – 367 = 200
200 shared over 2 steps → each step is 100
167, 267, 367, 467, 567, 667, 767, 867, 967, 1067
1672673674675676677678679671067
All ten fish filled in.
Why it happens: adding 100 changes only the Hundreds digit. After 967 the hundreds are full, so a Thousands place opens and we get 1067.
Was this helpful?