What Have We Discussed ?
1. When comparing two numbers, the one with
2. When forming numbers from a set of digits, make sure the conditions for making the number are satisfied. For example, to form the largest four-digit number using 6, 1, 9, 4 without repeating any digit, we arrange them in descending order:
3. The smallest four-digit number is
4. Using commas makes reading and writing large numbers easier. In the Indian numbering system, commas are placed after every
5. Large numbers are essential in various aspects of daily life. For instance, estimating the number of students in a city, the population of a village (or) town, transactions involving large sums of money (or) measuring distances between major cities.
6. Remember that kilo means
7. In some cases, exact numbers are unnecessary and an estimate is sufficient. For example, if reporting the attendance of an international cricket match, we might approximate it to 48,000 rather than stating the exact number.
8. Estimation means approximating a number to the required accuracy. For example, 5,243 can be rounded to 5,200 or 5,000, depending on whether we round to the nearest hundred or thousand.
9. In many situations, we estimate the outcome of arithmetic operations by rounding numbers and making quick calculations. This helps to save time and ensure accuracy.
10. Numbers are used in both the Indo-Arabic system and the International system, each with distinct ways of representing large numbers.
Indian place value chart
| Crores | Lakhs | Thousands | Ones | |||||
|---|---|---|---|---|---|---|---|---|
| Ten Crore | Crore | Ten Lakh | Lakh | Ten Thousand | Thousand | Hundred | Tens | Ones |
| 10,00,00,000 | 1,00,00,000 | 10,00,000 | 1,00,000 | 10,000 | 1,000 | 100 | 10 | 1 |
International place value chart
| Millions | Thousands | Ones | ||||||
|---|---|---|---|---|---|---|---|---|
| Hundred Million | Ten Million | Million | Hundred Thousand | Ten Thousand | Thousand | Hundred | Tens | Ones |
| 100,000,000 | 10,000,000 | 1,000,000 | 100,000 | 10,000 | 1,000 | 100 | 10 | 1 |
Units conversion table
| Mnemonic | Prefix | Relation with basic unit | Short Form | Scale |
|---|---|---|---|---|
| King | Kilo | 1 Kilo=1000 units | km =kilometer kL=kiloliter kg=kilogram | 10x10x10 LARGER than a unit |
| Henry | Hecto | 1 hecto=100 units | hm=hectometer hL=hectoliter hg=hectogram | 10x10x LARGER than a unit |
| Died | Deca | 1 deca=10 units | dam=decameter daL=decaliter dag=decagram | 10x LARGER than a unit |
| By | Basic Unit | 1 unit | m=meter L=liter g=gram | Meter (length) Liter (liquid volume) Gram (mass/weight) |
| Drinking | Deci | 10 deci = 1 unit | dm=decimeter dL=deciliter dg=decigram | 10x SMALLER than a unit |
| Chocolate | Centi | 100 centi = 1 unit | cm=centimeter cL=centiliter cg=centigram | 10x10x SMALLER than a unit |
| Milk | Milli | 1000 milli = 1 unit | mm=millimeter mL=milliliter mg=milligram | 10x10x10x SMALLER than a unit |