Class 7 Maths Chapter 8 Comparing quantities Exercise 8.2 pdf notes:-
- Exercise 8.1
- Exercise 8.3`
Exercise 8.2 Class 7 maths Chapter 8 Pdf Notes:-
Ncert Solution for Class 7 Maths Chapter 8 Comparing quantities Exercise 8.2 Tips:
PERCENTAGE – ANOTHER WAY OF COMPARING QUANTITIES
Anita’s Report Rita’s Report
Total 320/400 Total 300/360
Percentage: 80 Percentage: 83.3
Anita said that she has done better as she got 320 marks whereas Rita got only 300. Do
you agree with her? Who do you think has done better?
Mansi told them that they cannot decide who has done better by just comparing the
total marks obtained because the maximum marks out of which they got the marks are not
She said why don’t you see the Percentages given in your report cards?
Anita’s Percentage was 80 and Rita’s was 83.3. So, this shows Rita has done better.
Do you agree?
Percentages are numerators of fractions with denominator 100 and have been
used in comparing results. Let us try to understand in detail about it.
Meaning of Percentage
Per cent is derived from Latin word ‘per centum’ meaning ‘per hundred’.
Per cent is represented by the symbol % and means hundredths too. That is 1% means
1 out of hundred or one hundredth. It can be written as: 1% =1/100 = 0.01
Percentages when total is not hundred
In all these examples, the total number of items add up to 100. For example, Rina had 100
tiles in all, there were 100 children and 100 shoe pairs. How do we calculate Percentage
of an item if the total number of items do not add up to 100? In such cases, we need to
convert the fraction to an equivalent fraction with denominator 100. Consider the following
example. You have a necklace with twenty beads in two colours.
THINK, DISCUSS AND WRITE (i) Can you eat 50% of a cake? Can you eat 100% of a cake?
Can you eat 150% of a cake?
(ii)Can a price of an item go up by 50%? Can a price of an item go up by 100%?
Can a price of an item go up by 150%?