8 Ratioandproportion Lessonplan Vinay

# Instructional Objectives

- Discount is a reduction given on marked price.
- Discount = Marked Price – Sale Price.
- Discount can be calculated when discount percentage is given.
- Discount = Discount % of Marked Price
- Additional expenses made after buying an article are included in the cost price and are known as overhead expenses.
- CP = Buying price + Overhead expenses
- Sales tax is charged on the sale of an item by the government and is added to the Bill Amount.
- Sales tax = Tax% of Bill Amount
- Compound interest is the interest calculated on the previous year’s amount (A = P + I)
- Two quantities x and y are said to be in direct proportion if they increase (decrease) together in such a manner that the ratio of their corresponding values remains constant. That is if x/y= k [k is a positive number], then x and y are said to vary directly. In such a case if y
_{1}, y_{2}are the values of y corresponding to the values x_{1}, x_{2}of x respectively then x_{1}/y_{1}= x_{2}/y_{2} - Two quantities x and y are said to be in inverse proportion if an increase in x causes a proportional decrease in y (and vice-versa) in such a manner that the product of their corresponding values remains constant. That is, if xy = k, then x and y are said to vary inversely.In this case if y
_{1}, y_{2}are the values of y corresponding to the values x_{1}, x_{2}of x respectively then x_{1}y_{1}= x_{2}y_{2}

# Teaching process

- Slightly advanced problems involving applications on percentages, profit & loss, overhead expenses, Discount, tax.
- Difference between simple and compound interest (compounded yearly up to 3 years or half-yearly up to 3 steps only), Arriving at the formula for compound interest through patterns and using it for simple problems.
- Direct variation – Simple and direct word problems
- Inverse variation – Simple and direct word problems
- Time & work problems – Simple and direct word problems

# Special needs

- Catch up worksheets and IEP

# Evaluation Tools

- Constant evaluation in class through interactions
- Worksheets and unit tests