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 y1 , y2 are the values of y corresponding to the values x1 , x2 of x respectively then x1/y1 = x2/y2
• 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 y1 , y2 are the values of y corresponding to the values x1 , x2 of x respectively then x1 y1 = x2 y2

# 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