Village Number Works
Align ones, tens and hundreds. For addition trade ten of one place for one of the next. For subtraction a larger unit can be exchanged for ten smaller units.
Before you try
Before you play, make a prediction: What is 58 + 27? Explain what you expect and what part of the model will help you check it.
Try it out
Interactive activity
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What happened?
Move a control to see what changes and why.
The game practises one idea at a time with simple drawn pictures. Check the same idea with real objects and your NCERT textbook (Chapter 7: The Cleanest Village, pages 95–114).
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Try these ideas
- Estimate to the nearest ten, then build the exact answer with place-value wheels.
- Try a new puzzle with ↻. Describe what changed and which mathematical rule stayed the same.
- Complete a round, then explain your method before you move to the next one.
Why it works
Align ones, tens and hundreds. For addition trade ten of one place for one of the next. For subtraction a larger unit can be exchanged for ten smaller units.
308 − 129 = 179. Regrouping preserves the total while making subtraction possible. Estimate to the nearest ten, then build the exact answer with place-value wheels.
When regrouping through zero, preserve the value at every exchange.
This activity connects to The Cleanest Village, NCERT Class 4 maths, printed pages 95–114. Use the picture or objects to explain each step before relying on a calculation. The game practises one part of the chapter at a time; the other three activities extend the chapter’s ideas.
Worked example: Calculate 403 − 178. Exchange one hundred for ten tens, then one ten for ten ones: 403 becomes 3 hundreds, 9 tens and 13 ones. Subtract by place: 13 − 8 = 5, 9 − 7 = 2, 3 − 1 = 2. The result is 225.
Check your understanding
Question 1 of 2
What is 58 + 27?
An estimate of 298 + 203 is closest to…
Explain it in your own words
What changed? Why did it happen? Where might you notice this in everyday life?
For parents & teachers
- Try with everyday materials. Estimate to the nearest ten, then build the exact answer with place-value wheels. Ask the child to make a new example using paper, counters, household objects or a labelled sketch.
- Listen to the explanation. When regrouping through zero, preserve the value at every exchange. Ask “How could we check?” and encourage a second representation of the same idea.