## Knowing Our Numbers Class 6 Notes

1. To represent any number, we use ten symbols, namely 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 which are called digits or figure.

2. Numbers help us to compare collection of two or more similar objects and we can decide which collections is bigger or smaller.

3. Comparison of numbers helps us to arrange the objects in increasing or decreasing order.

4. If we shift the digits of a given number, then the new number is different from the original one. 853 is different from 358 but 202 remains same even after changing the unit place and hundredth place of the number. Why?

5. If we add one more to the greatest 5-digit number, we get the smallest 6-digit number

99999 (5-digit) + 1 = 100000 (6-digit).

6. Generally, numbers are written in two types of charts:

- Hindu Arabic Place – Value Chart
- International Place – Value Chart.

7. Estimation gives us a rough idea of the answer to a question involving operations on number.

8. In Roman numeration system, only symbols are used to express a number instead of digits.

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

9. Zero on the extreme left of a number has no value.

10. Ascending order means arrangement from the smallest to the greatest.

11. Descending order means arrangement from the greatest to the smallest.