Comparing Quantities Part 5 " Conversion of Ratio to Percentage"

Class 7 Mathematics Chapter 8 Comparing Quantities

1. Class 7 Mathematics Chapter 8 Integrated B.Sc. - B.Ed. Name : SANDHYA School Of Education Comparing Quantities Part 5

2. Identify the Food Item

3. Identify the Image

4. You must take two parts of rice and one part of urad dal What is the ratio of rice to urad dal ? What is the fraction of rice and urad dal?

5. You must take two parts of rice and one part of urad dal What is the ratio of rice to urad dal ? 2:1 What is the fraction of rice and urad dal?  

6. What percentage of such a mixture would be rice ? What percentage would be urad dal? What is the ratio of rice to urad dal ? 2:1 What is the fraction of rice and urad dal?  

7. Conversion of Ratio to Percentage Ratio to percentage is the conversion procedure, which helps to convert the ratio into a percentage. Ratio to percentage conversion helps us in obtaining accuracy in mixtures of elements.

8. Conversion of Ratio to Percentage Steps to convert a ratio to a percent are given below: Step 1:  Identify the ratio. Step 2:  Express the ratio a:b in the form of a fraction a/b. Step 3:  Multiply the fraction by 100.

9. Conversion of Ratio to Percentage Steps to convert a ratio to a percent are given below: Step 1:  Identify the ratio. Step 2:  Express the ratio a:b in the form of a fraction a/b. Step 3:  Multiply the fraction by 100. Step 4:  Simplify and write the answer with the percent symbol (%). Convert the ratio 5: 4  

10. Your mother said, to make idlis, you must take two parts rice and one part urad dal. What percentage of such a mixture would be rice ?

11. In terms of ratio ,we would write this as Rice : Urad dal = 2 : 1 Now, 2 + 1=3 is the total of all parts. Then, percentage of rice = * 100 = 66%   Your mother said, to make idlis, you must take two parts rice and one part urad dal. What percentage of such a mixture would be rice ?

12. In school , science stream students have the freedom to choose between Computer Science and Economics . The ratios of students with Computer Science to students with Economics is 3:2. Express students who have opted for Economics as percentage of the total number of students in the science stream.

13. In school , science stream students have the freedom to choose between Computer Science and Economics . The ratios of students with Computer Science to students with Economics is 3:2. Express students who have opted for Economics as percentage of the total number of students in the science stream. Ratio of students with Computer Science to students with Economics = 3:2 Total number of Science student = 3 + 2= 5 Economics students in every Science students= 2 Economics students in every 100 Science students = 40% 4 0% of the Science students have opted for Economics.  

14. Convert 3:1 to percentage using the steps of ratio to percent conversion.

15. Convert 3:1 to percentage using the steps of ratio to percent conversion. Step 1: Write the ratio in fractional form. So, 3:1 =   Step 2: Multiply the fraction obtained by 100. This implies × 100   Step 3: So, × 100 = 300%  

16. If Rs 250 is to be divided amongst Ramesh , Sandeep and Suman so that Ramesh gets two parts, Sandeep three parts and Suman five parts. How much money will each get?

17. If Rs 250 is to be divided amongst Ramesh , Sandeep and Suman so that Ramesh gets two parts, Sandeep three parts and Suman five parts. How much money will each get? The parts which the three boys are getting can be written in terms of ratios as 2 : 3 : 5 Total of the parts is 2 + 3 + 5 = 10 Amounts received by each: × Rs 250 = Rs 50 (Ramesh) ×Rs 250 = Rs 75 (Sandeep) × Rs 250 = Rs 125 (Suman)  

18. If Rs 250 is to be divided amongst Ramesh , Sandeep and Suman so that Ramesh gets two parts, Sandeep three parts and Suman five parts. What will it be in percentages? Ramesh Sandeep Suman

19. If Rs 250 is to be divided amongst Ramesh , Sandeep and Suman so that Ramesh gets two parts, Sandeep three parts and Suman five parts. What will it be in percentages? Ramesh: 20 %   Sandeep: = 30%   Suman: = 50%  

20. RECAPITULATION: Ratio to percentage is the conversion procedure, which helps to convert the ratio into a percentage. Estimate what part of the figures is coloured and hence find the per cent which is coloured.

21. RECAPITULATION: Asish received his monthly salary. The ratio of his expenditure to savings is 7:3. What percentage of his salary, did he spend and what percentage was saved by him?

22. HOMEWORK: Q.1) (i) Chalk contains calcium, carbon and oxygen in the ratio 10:3:12. Find the percentage of carbon in chalk. (ii) If in a stick of chalk, carbon is 3g, what is the weight of the chalk stick. Q.2) Estimate what part of the figures is coloured and hence find the per cent which is coloured. Q.3) The primary grade students of a school are divided into two houses - red house and blue house. If the ratio of students of the blue house to the red house is 4:5, find the percentage of blue house students in the school using the ratio to percent conversion formula.