Comparing quantities: percentages and profit: Class 7 maths video

0:00 Class 7 maths. Comparing quantities: percentages and profit.

0:05 Welcome aboard the Captain Calc Math Squad!

0:08 Today we are mastering percentages and finding out how shopkeepers calculate profit and loss.

0:15 Understanding Percentages and Conversions.

0:18 Percent means per hundred.

0:21 We write it using the % symbol.

0:23 Try this one. Convert 3/5 into a percentage.

0:29 Multiply 3/5 by 100.

0:33 (3 / 5) × 100 = 3 × 20 = 60%.

0:39 So the answer is 60%.

0:41 Finding Quantities and Percentage Change.

0:45 To find a percentage of a number, multiply the number by the percentage fraction.

0:50 Percentage increase or decrease tells us how much a quantity changed compared to the original amount.

0:57 Try this one. Find 20% of ₹500.

1:03 Write 20% as 20/100.

1:07 (20 / 100) × 500 = 20 × 5 = 100.

1:13 So the answer is ₹100.

1:17 Cost Price, Selling Price, Profit, and Loss.

1:21 Cost Price (CP) is the buying price of an item.

1:25 Selling Price (SP) is the price at which it is sold.

1:29 Try this one. Rahul buys a book for ₹150 and sells it for ₹180. Find the profit.

1:40 CP = ₹150 and SP = ₹180.

1:47 Since SP > CP, Profit = 180 - 150 = ₹30.

1:56 So the answer is ₹30.

1:59 Calculating Profit Percentage and Loss Percentage.

2:03 Profit percentage and Loss percentage are always calculated on the Cost Price (CP).

2:09 Profit % = (Profit / CP) × 100.

2:15 Try this one. CP = ₹400 and Profit = ₹80. Find Profit %.

2:24 Profit % = (Profit / CP) × 100.

2:29 Profit % = (80 / 400) × 100 = 80 / 4 = 20%.

2:37 So the answer is 20%.

2:40 Your turn. Express 7/20 as a percentage (in %). Pause the video, and try it.

2:49 The answer is 35.

2:52 Well done! Now try the practice and the quiz in this lesson on LearnFun.