Class 7 Chapter 9: Percentage and Its Applications

Important Concepts and Formulas

1.    Per cent means per hundred or for every hundred.

2.    The numerator of a fraction with denominator 100 represents percentage.

3.    To convert a fraction into a per cent, multiply the fraction by 100.

4.      To convert a ratio into a per cent, write it as fraction and multiply it by 100.

5.      To convert a decimal into a per cent, shift the decimal point two places to the right.

6.      To convert a per cent into a fraction, divide it by 100 after removing the symbol of %.

7.      Increase = Increased value – Original value.

8.      Percentage increase = (Increase/Original value) × 100% and increased value = (100% + increase %) × original value.

9.      Decrease = Original value – Decreased value.

10. Percentage decrease = (Decrease/Original value) × 100% and decreased value = (100% – decrease %) × original value.

11. Profit = S.P. – C.P. and Loss = C.P. – S.P.

12. Profit% = (Profit/C.P.) × 100 and Loss% = (Loss/C.P.) × 100.

13. Simple Interest (SI) = (P × R × T)/100 and Amount = P + SI.

14. Rate per cent = (SI × 100)/(P × T)

15. Time = (SI × 100)/(P × R)

16. Principal = (SI × 100)/(R × T)