Large Numbers Around Us
The Land of Tens
Visit the Land of Tens, where special calculator buttons teach you about place value.
In the Land of Tens, each calculator has special buttons. How many presses for a number? Divide the number by the button's value.
| Calculator | Button | Some presses |
|---|---|---|
| Thoughtful Thousands | +1000 | 3000 → 3; 10,000 → 10; 53,000 → 53; 90,000 → 90; 1 lakh → 100; 153 presses → 1,53,000 |
| Tedious Tens | +10 | 500 → 50; 780 → 78; 1000 → 100; 3700 → 370; 10,000 → 1000; 1 lakh → 10,000 |
| Handy Hundreds | +100 | 400 → 4; 3700 → 37; 10,000 → 100; 1 lakh → 1000 |
So 100 thousands make a lakh, and 100 hundreds make ten thousand.
Handy Hundreds boasts: There are numbers that Tedious Tens and Thoughtful Thousands can't show, but I can. Is it true? Against Thoughtful Thousands, yes: it cannot show 100, 200, 300. Against Tedious Tens, no: every number Handy Hundreds shows (100, 200, ...) is also a multiple of 10. So the boast is not true for both.
Creative Chitti has +1, +10, +100, +1000, +10000, +100000 and +1000000, and always finds many ways. For 321: +10 thirty-two times and +1 once; or +100 twice, +10 twelve times and +1 once. For 5072:
- (50 × 100) + (7 × 10) + (2 × 1) = 5072
- (3 × 1000) + (20 × 100) + (72 × 1) = 5072
Chitti's puzzle: with exactly 30 presses, what are the largest and the smallest 3-digit numbers you can make?
Systematic Sippy wants the fewest clicks. For 5072: +1000 five times, +100 zero times, +10 seven times, +1 twice — 14 clicks. Look at those counts: 5, 0, 7, 2, the digits of 5072 itself! The fewest-clicks way is always the number's expanded form, which is exactly what place value means.
Practise this lesson
Questions that get harder as you improve, a Tutor that helps without giving the answer away, and progress you can see. Free for every learner.
No account, no email address. Opens the real product.