How To Calculate Percentage Change

Hi. My name is Charles and I'm one of the math teachers from the Maxim workshop. I'm just now going to teach you how to do some math.

In the video, I'm going to show you how to calculate percentage change. Now percentage is something you obviously need to understand when you might want to go buy something on sale because you want to know the percentage change that they are offering and say possibly a discount is the one reflective on the price label. So what I'm going to do is set up a scenario whereby we have an item in a shop that's on sale and we're going to calculate the percentage change and obviously, that would be reflective of the discount.

So you have this jacket and you can see that the tag says, "20% off." Now what we want to do is associate this jacket with this original price. The original price, that it was sold at, was 40 pounds.

So now the next step is to actually figure out what a percentage change in terms of a discount would relate to on this price here, which is the original price. The first thing we want to do is calculate what 1 % of 40 Pounds is. A percent measures one part in a hundred, so we want to divide this by 100.

That just means that we have to, as many zeros as we have in the denominator, we jump to the left. So one, two. So we have 0.

4 pounds which is basically 40 pence. Now, we have 1% of the original price. We want to find out how that relates to a percentage change of 20%.

So what we need to do is multiply this by 20 and that will give us 20%. 20 times 0.4 gives us the following.

If we want to multiply 20 by 0.4, the easiest thing to do is first multiply the 2 by 0.4 that will give us 0.

8 pounds and we still have the multiplication of the 10 here. That will give us 10 times the 0.8 which is just 8 pounds.

So you can see when we divide by a 1 and 0, we basically move to the left. Now when we multiply by 1 and 0, as many zeros as we find, we just move to the right. So that jumps this decimal point over here, and we've got 8 pounds.

So 20% of 40 pounds is just 8 pounds. So now obviously if we are looking for a 20% discount from the original price, we want to subtract this 8 pounds from this 40 pounds and that goes like this. So a percentage change or discount of 8 pounds from 40 pounds is equal to 32 pounds.

Now, remember the first thing you want to figure out is what 1% relates to and then you can figure out. Then you can multiply it by how many percent you want give the discount price. Once you've got that measurement, you can subtract it from the original price to give you the discounted price and that's basically how you calculate percentage change. .