NCERT Solutions for Class 4th Maths Chapter 11 . Letters on the ambulance — In-text Questions
Book page 1693 Updated on2026-09-19
Q1.
What do you notice about the letters written on the ambulance? Why are they written this way? Discuss.
Answer
The word is written back to front, like a picture in a mirror.
The front of an ambulance, with the word painted the way it is printed in the book.
It is written this way so that the driver in front can read it.
A car driver sees the ambulance in the mirror above the windscreen.
The mirror turns the word back to front once more.
So the driver reads AMBULANCE the right way round.
Why it happens: A mirror always flips left and right. The painter flips the word first, so the mirror flips it back and it reads correctly.
Check it yourself: Hold this page up to a mirror. The word on the ambulance will read normally.
Q2.
Can you guess what I have written? Where did I keep the mirror?
Answer
The word is CAT. The mirror was kept above (or below) the word, lying across it.
The word as it is printed in the book.
Look carefully at each letter:
C is the same when turned upside down, so it looks unchanged.
A is printed upside down, like ∀.
T is printed upside down, like ⊥.
The letters are still in the order C, A, T — they have not been swapped.
Why it happens: A mirror kept above the word flips it top to bottom, so each letter turns over but the order stays the same. A mirror kept at the side would have reversed the order to T, A, C.
Q3.
Can you identify these words? Where will you place the mirror to read the following words correctly?
Answer
The four words are TAP, CAN, WOW and HEN.
The four words as they are printed in the book.
Printed word
The real word
Where to keep the mirror
first word
TAP
At the side (left or right) — the letters are in reverse order
second word
CAN
Above or below — each letter is upside down, order unchanged
third word
WOW
At the side — it is printed the same because WOW is its own mirror image
fourth word
HEN
At the side — the letters are in reverse order
Why it happens: A mirror at the side reverses the order of the letters. A mirror above or below turns each letter upside down but keeps the order. Looking at whether the order has changed tells you where the mirror was kept.
Did you know? W, O, W each look the same in a side mirror, and WOW reads the same from both ends. That is why WOW looks perfectly normal in the book.
Q4.
Now, you try to write some words/names in this way and challenge your friends to guess them.
Answer
Write the word on thin paper, then trace it from the back of the sheet. That gives you the mirror writing.
Write your word in big block letters, for example MILK.
Turn the sheet over and hold it against the window.
Trace the word from the back — that copy is the mirror writing.
Sample answer: I wrote MILK, RANI and BUS in mirror writing and my friends read them with a small mirror.
Tip: Words like MOM, TOOT and WOW are fun — they look almost unchanged.
Q5.
Can you also try doing this with the script of your own language?
Answer
Yes. Mirror writing works in every script.
Write a short word in your own script, such as माँ or घर.
Trace it from the back of the sheet to get the mirror form.
Read it with a mirror kept at the side.
Sample answer: In Hindi the letter म changes a lot in a mirror, but the shape ल written plainly is easier to read back.
Why it happens: A mirror only flips left and right. It does not care which language the letters belong to.
Q6.
Complete the following to make symmetrical shapes.
Answer
Each small drawing is only a part of a shape. Add lines so that the finished shape can be folded into two matching halves.
The six part-drawings printed on the dot grid.
Sample answer: here is one way to finish each one.
The added lines are shown dashed in red.
Part-drawing
Shape made
Lines of symmetry
Corner with a long arm and a short arm
Rectangle
2
Two slanting lines meeting at a point
Triangle with two equal sides
1
Corner with two equal arms
Square
4
One standing line
Square
4
L-shape of two equal arms
Square
4
One sleeping line
Rectangle
2
Why it happens: Counting dots keeps every new line the same length as its matching line, so the finished shape folds neatly on itself.
Tip: There is more than one right answer. Your friend may close the same part-drawing into a different symmetrical shape.