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Concept 4 of 7

Reading & Writing Large Numbers

Free
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Today's big idea

Read from the leftmost group, saying its value and then the name of that group.

An empty group is silent when read aloud, but its zeros must still be written.

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How it works

👀 What's going on?

Turning a long number into words, or words back into a number, is where a careful child still loses a mark. The digits are never the difficulty. Keeping the groups lined up is.

💡 Here's the trick

Number ↔ Words8,02,40,1098crore02lakh40thousand109onesEight crore, two lakh, forty thousand,one hundred and nine.

Look at the number above. Reading starts at the leftmost group, says how many are in it, then names the group, and moves right. Writing runs the same process backwards, and every group must be filled even when nothing is said aloud for it.

🪄 How to do it

  1. 1.Split the number above into its comma groups.
  2. 2.Working left to right, say the value of a group and then its name.
  3. 3.To write from words, lay out empty groups first and drop each value in.

✍️ Try it

Write in figures: six crore, four lakh, twenty thousand, nine. Then read 3,00,05,070 aloud.

The first is 6,04,20,009. The second reads as three crore, five thousand and seventy, because the lakhs group is empty and simply is not spoken.

⚠️ Watch out

You might be thinking a group you do not say aloud does not need writing. It does. Nobody says any lakhs in 3,00,05,070, but drop those two zeros and the number collapses from three crore to three lakh.

🌟 Why this matters

Cheques, forms and official records all ask for a number in both figures and words, and the two have to agree. Getting them to match is the whole task.
Exam tip: Draw the empty comma groups first, then fill them, so a silent group cannot go missing.

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Watch me solve one

Quanta solves it

“Watch how I think through one of these — then you try.”

THE PROBLEM

“Write “Two crore, fifteen lakh, three hundred” in digits.”

  1. 1

    Break period by period

    2 crore · 15 lakh · 0 thousand · 300. 🗣️

  2. 2

    Stack the periods

    Crore: 2 · Lakh: 15 · Thousand: 00 · Ones: 300.

  3. 3

    Glue with Indian commas

    2,15,00,300

  4. 4

    Answer ✓

    2,15,00,300

Now you try one — same steps, different story 👇

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See it in action

⚡ Time to play!

Tap each period in turn — say the chunk, then place its digits. Watch the zeros.

BUILD THE NUMBER · ROUND 1 OF 3

Four million, sixty thousand, two hundred

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Quick check

✅ VERIFICATION

Which number is 'two lakh, sixty thousand, four'?

⚡ Finish the activity above first to answer.

Keep going!

Up next: Roman Numerals

I V X L C D M, add or subtract by position.

Concept 5 of 7