RATIO & PROPORTION

1. RATIO & PROPORTION

2. Hierarchy Order
• Fraction
• Equivalent Ratios
• Ratios
• Unitary Method
• Proportion
• Direct proportion
• Inverse Proportion
• continued proportion

3. Learning Objectives
• • Understand the concept of ratio
• • Use the notation and simplify ratio
• • Divide the quantity of things in the given
ratio
• • Recognize the relationship between ratio
and proportion
• Solve simple problems by unitary method

4. Warm up activities
• 1. Note the attendance of class VI and class
VII.
• 2. Note number of days of any two months
and how will you compare?

5. Example
• Weight of a bag is 4 kg and weight of a chair is
7 kg, then the ratio of the weight of a bag and
the chair is 4 : 7.4.7 cannot be replaced by 7:4.

6. Explain
• • Through pictures, ratio should be explained
by the teacher.
• • Can you compare your weight with the
weight of an elephant which weighs 3500 kg
.Compare and find the ratio between your
Weight and Elephant’s Weight.

7. Class Assessment
• 1. The ratio between 15 boys and 13 girls
is__________________
• 2. If the cost price of a ball is Rs.60 and the
weight of a wrist watch is 20gm Can you compare
this and why?
• 3. Compare and find the ratio between 1 hour
and 30 minutes
• 4. In a bag containing 23 apples, 11 apples are
rotten. Find the number. of good apples and then
find out the ratio of number of rotten and good
apples.

8. Writing the ratios in the simplest
form, Conversion of different units
to same units

9. • How to simplify the fraction – taught
• • Consider a rectangle of length 12m and
breadth 800cm
• length =12m and b = 800 cm
• Breadth = 800 cm = 800 /100 m = 8 m
• Ratio of length to breadth is 12/8 = 3/2 = 3 : 2

10. Assessment
• If the base of a triangle is 70cm and height is 25cm.
Find the ratio of the height to the base
• • Find the simplest form of the following
• i. 2 and 6
• ii. 16/20
• iii. 24:4
• iv. 20 m to 600 cm
• v. 15 lt to 3 lt 750 ml
• vi. 5 kg 800 gm to 29 kg
• vii. 3 days to 6 hours
• viii. 20 students to 4 rows