NCERT Solutions for Class 4th Maths Chapter 6 Measuring Length — Let Us Observe
Book page 80 Updated on2026-09-19
Q1.
Look at the picture. What are the students measuring? Put a tick mark (✓) if you find it being measured. a) Length b) Height c) Weight d) Depth e) Breadth f) Temperature
The picture on page 80: a school health camp in a classroom. A banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat machine that has a cord running from it. In the middle a doctor and a nurse are checking two children with a small flat stick. On the right a boy stands straight on a low platform, with his back against a tall marked strip fixed to the wall, and a teacher places his hand flat on top of the boy’s head.
What the picture in your book shows.
Answer
The picture on page 80: a school health camp in a classroom. A banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat machine that has a cord running from it. In the middle a doctor and a nurse are checking two children with a small flat stick. On the right a boy stands straight on a low platform, with his back against a tall marked strip fixed to the wall, and a teacher places his hand flat on top of the boy’s head.
What the picture in your book shows.
Tick b) Height and c) Weight.
What
Tick
Who is doing it in the picture
a) Length
✘
Nobody is measuring a length lying flat
b) Height
✔
The boy standing against the marked strip on the wall
c) Weight
✔
The girl standing on the machine with a cord
d) Depth
✘
Nothing deep, like a well, is being measured
e) Breadth
✘
Nobody is measuring how wide something is
f) Temperature
✘
No thermometer is being used. The doctor is only looking inside the mouth
Why it happens: We tick only what we can actually see being measured in the
picture. Two things are being measured here — how tall the children are, and how heavy they are.
Tip:Height is a length. Tall, wide, deep and broad
are all words for a length. We choose the word by the way the thing stands.
Q2.
What is being used to measure the height? What other tools can be used to measure height?
The picture on page 80: a school health camp in a classroom. A banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat machine that has a cord running from it. In the middle a doctor and a nurse are checking two children with a small flat stick. On the right a boy stands straight on a low platform, with his back against a tall marked strip fixed to the wall, and a teacher places his hand flat on top of the boy’s head.
What the picture in your book shows.
Answer
The picture on page 80: a school health camp in a classroom. A banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat machine that has a cord running from it. In the middle a doctor and a nurse are checking two children with a small flat stick. On the right a boy stands straight on a low platform, with his back against a tall marked strip fixed to the wall, and a teacher places his hand flat on top of the boy’s head.
What the picture in your book shows.
A long measuring scale fixed to the wall is being used. The boy stands
straight on a flat platform with his back to the scale, and the teacher reads the mark at the top of
his head.
Other tools we can use to measure height:
a measuring tape, like the one a tailor uses;
a 1 metre rope that we made ourselves;
a metre scale or a long ruler;
a stick with marks on it, held straight against the wall.
Why it happens: Any tool with equal marks on it can measure height. The tool
must be straight, and the child must stand straight with feet flat on the floor.
Check it yourself: Put a mark on the wall at the top of your head. Then
measure from the floor to that mark with a tape. You get the same answer.
Q3.
Recall in Grade 3 you studied that lengths are measured in metres. Check and fill in the blanks whether the following are correct/incorrect for your classroom. a) The height of most of the students in my grade is more than a metre. _______________
Answer
Correct.
1 m = 100 cm
Height of most Grade 4 children = about 120 cm to 140 cm
120 cm is more than 100 cm → more than 1 m
How to check:
Stand straight against a wall with your heels touching it.
Ask a friend to put a ruler flat on your head and mark the wall.
Measure from the floor to the mark with a measuring tape.
Compare that number with 100 cm.
Sample answer: Correct. In my class 32 children out of 35 are taller than 1 m.
Why it happens: A metre is only 100 cm, which is about up to the waist of a
grown-up. Most nine-year-olds are already taller than that.
Q4.
b) The length of my arm is less than a metre. _______________
Answer
Correct.
Length of my arm = about 55 cm
55 cm is less than 100 cm → less than 1 m
How to check: Stretch your arm out straight. Lay the measuring tape from your shoulder to
the tip of your longest finger and read the mark.
Sample answer: Correct. My arm is 55 cm long, which is a little more than half a metre.
Why it happens: Your whole body is about 130 cm tall, so one arm must be much
shorter than that — about half a metre.
Q5.
c) The height of the door of the grade is less than a metre. __________
Answer
Incorrect.
Height of the classroom door = about 2 m
2 m = 200 cm, and 200 cm is more than 100 cm
So the door is more than a metre, not less
How to check: Stand your 1 m rope on the floor beside the door. Mark the top of the rope,
then lift the rope and place it again from that mark. The rope fits about two times.
Sample answer: Incorrect. The door of my classroom is about 2 m high.
Why it happens: A grown-up is taller than 1 m and still walks through the
door without bending. So the door must be taller than 1 m.
Q6.
d) The breadth of the blackboard is more than a metre.___________
Answer
Correct.
Breadth (the side-to-side length) of the blackboard = about 2 m
2 m = 200 cm, which is more than 100 cm → more than 1 m
How to check: Hold the 1 m rope along the bottom edge of the blackboard. Mark where it
ends, then move the rope again from that mark. It fits about two times.
Sample answer: Correct. My blackboard is 2 m broad.
Why it happens: The whole class has to see the blackboard, so it is made
wide — wider than one metre rope.