Knowing Our Numbers 🔢

Numbers keep growing — thousands, lakhs, and now crores. Once you can read, compare and round a really big number, you can also read and write it the ancient Roman way.

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Part 1 · Place Value to Crores

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Part 2 · Comparing & Estimating

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Part 3 · Roman Numerals

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Mock Test

Place Value to Crores 🏛️

After lakhs comes an even bigger group — crores. 1 crore = 100 lakh = 1,00,00,000.

3,45,67,890 broken into places

Crore	Ten-lakh	Lakh	Ten-thousand	Thousand	Hundred	Ten	One
3	4	5	6	7	8	9	0

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International system: the rest of the world groups numbers as ones, thousands and millions instead of lakhs and crores. 1 million = 10 lakh, and 1 crore = 10 million.

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Game 1 — What Is the Digit Worth?

Comparing & Estimating 🎯

Estimating means replacing a number with a simpler, nearby one — useful for a quick, rough check of an answer.

🪜 Rounding rule (recap)

Look at the digit right after the place you are rounding to. 5 or more → round up. 4 or less → round down.

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Game 2 — Round It

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Game 3 — Which One Is Bigger?

Roman Numerals 🏺

Ancient Rome had no zero and no place value — just seven symbols, combined by two simple rules.

I	V	X	L	C	D	M
1	5	10	50	100	500	1000

🔑 Two rules

Add when a smaller symbol follows a bigger one: VI = 5 + 1 = 6.
Subtract when a smaller symbol comes BEFORE a bigger one: IV = 5 − 1 = 4.

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Game 4 — Match the Roman Numeral

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Game 5 — Odd One Out

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Knowing Our Numbers Mock Test

12 IMO-style questions on place value, estimation and Roman numerals. 🍀

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Whole Numbers 🔵