CBSE Class 3 · Mathematics
House of Hundreds – I
Official NCERT chapter from Maths Mela (book code cemm1). ExamMaster notes are original teaching at CBSE Class 3 depth.
This lesson follows the official chapter “House of Hundreds – I” in Maths Mela. The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.
- CBSE Class 3
- Easy level
- 8 concepts
1A mela guess “more than a hundred” is a compare
“More than a hundred” compares a pile to one hundred-bundle. It is not yet an exact count.
Treat it as a first compare. Then finish the bundles if you need the exact number.
Figure. “More than a hundred” is a compare to one finished hundred-bundle. The pile bar is longer than 100; that is not yet the exact count.
How it works
- Name the benchmarkOne hundred.
- Ask more, less, or not sureA compare.
- Count if you need exactGuess is not the numeral.
2Hundred is ten tens
Ten finished tens trade for one hundred. That hundred opens the hundreds house.
Nine tens are not a hundred.
Figure. Ten finished tens trade for one hundred. Nine tens do not open the hundreds house. The trade is a bundle, not a new kind of number.
How it works
- Make ten tensEach ten is 10 ones.
- Trade for 1 hundredNew house.
- Write 1 in hundredsOnes and tens may still have leftovers.
3Read 247 as 2 hundreds, 4 tens, 7 ones
247 is two hundred-bundles, four tens, seven ones. Read the houses; do not say “twenty-four seven”.
The 2 is not 2 ones.
Figure. 247 is two hundreds, four tens, seven ones. Read the houses. The 2 is not two ones.
How it works
- Hundreds digit2 → 200.
- Tens digit4 → 40.
- Ones digit7 → 7.
Read 368 by houses
Write 368 as hundreds, tens, and ones.
- Hundreds3
- Tens6
- Ones8
- Value300 + 60 + 8
Pro tip. Left house first. Each digit has its own value.
4Triangular torans can be bundled in tens then hundreds
Decorations are still ones. Bundle them: ten ones make a ten; ten tens make a hundred.
The triangle shape does not change the bundling.
Figure. Decorations are still ones. Ten ones make a ten; ten tens make a hundred. The triangle shape of a toran does not change the bundling.
How it works
- Count onesEach toran is one.
- Bundle tensTen ones each.
- Bundle hundredsTen tens each.
5Compare two three-digit numbers from the left
356 and 298: hundreds 3 > 2, so 356 is more. Tens wait their turn.
Starting at ones can fool you.
Figure. Compare three-digit numbers from the hundreds house. 3 is greater than 2, so 356 is more than 298. Tens wait their turn.
How it works
- Compare hundredsDecide if you can stop.
- Then tensOnly if hundreds match.
- Then onesLast.
6The next hundred is a new bundle
After 199, one more one makes 200 — a new hundred-bundle, not “100 + 99 + 1” said as a jumble.
Crossing into the next hundred is a house change.
Figure. After 199, one more one makes 200 — a new hundred-bundle. The ones and tens houses empty; the hundreds digit steps from 1 to 2.
How it works
- See 9 tens and 9 onesAlmost the next hundred.
- Add one oneTrade up.
- Write the new hundreds digit200, 300, …
7Zero holds the tens house open in 205
205 is 2 hundreds, 0 tens, 5 ones. The zero is the empty tens house.
Writing 25 would slide the 2 into tens.
Figure. 205 is 2 hundreds, 0 tens, 5 ones. The zero holds the tens house open. Writing 25 would slide the 2 into tens.
How it works
- Read 2 as hundreds200.
- Read 0 as no tensHouse still there.
- Read 5 as ones205.
8A guess is not a count until you finish the bundles
“Looks like more than 200” can start you. The count ends only when ones, tens, and hundreds are finished.
Stopping at the guess leaves the hundreds house unread.
Figure. A guess can start you. The count ends only when hundreds, tens, and ones are written. Stopping at “more than 200” leaves the houses unread.
How it works
- Allow a first guessMore than a hundred, or not.
- Then bundleOnes → tens → hundreds.
- Write the three-digit numeralThat is the count.
In 247 the digit 2 names
- 2 hundreds
- 2 tens
- 2 ones
Left house is hundreds.
Notes
- The official chapter title is “House of Hundreds – I”. Teach the school test for that title, not a contest shortcut.
- If a step needs a later class, stop. The next official chapter will pick it up.
Formulas
- 247 = 2\times 100 + 4\times 10 + 7.
- Compare three-digit numbers from the hundreds house first.
Recap
Hold these pegs from the official chapter “House of Hundreds – I”. The wording is ExamMaster’s teaching, not a textbook recap.
- A mela guess “more than a hundred” is a compare
- “More than a hundred” compares a pile to one hundred-bundle.
- Hundred is ten tens
- Ten finished tens trade for one hundred. That hundred opens the hundreds house.
- Read 247 as 2 hundreds, 4 tens, 7 ones
- 247 is two hundred-bundles, four tens, seven ones.
- Triangular torans can be bundled in tens then hundreds
- Decorations are still ones. Bundle them: ten ones make a ten; ten tens make a hundred.
- Compare two three-digit numbers from the left
- 356 and 298: hundreds 3 > 2, so 356 is more.
- The next hundred is a new bundle
- After 199, one more one makes 200 — a new hundred-bundle, not “100 + 99 + 1” said as a jumble.
Practise House of Hundreds – I
Reading is free and needs no account. Practice, mocks and progress live in the app.
- A 4-question practice set that ends the chapter
- 1 quick check with worked explanations
- Timed mocks scored with the real marking scheme
- Readiness tracked per topic, kept on your device