Write a mathematical journal (with length and area units required)

Write a mathematical journal (with length and area units required)

Today, I went to the supermarket and bought a carpet. It is 3 meters long, 2 meters wide and covers an area of 6 square meters

Mathematics diary
It can be shopping malls for activities and cinemas for seats
Notice that I'm in grade six

On Sunday, my mother and I went shopping in the mall. The poster in the supermarket said, "if you buy more than 200 yuan, return 100 yuan voucher." I thought to myself, "ha ha, if you buy more than 200 yuan, return 100 yuan, that's half of the original price. It's very cost-effective."
I chose a set of 208 yuan sportswear for myself and got a token of 100 yuan. The token had to be used up today, so my mother bought a 288 yuan juicer for my sick grandfather. I calculated that I could buy the juicer with 188 yuan
After shopping, on the way home, I said to my mother: "Mom, today we buy these things are not a 50% discount?" mother said with a smile: "silly child, it's not like this. When we go home, my mother will show you, you will know."
When I got home, my mother said to me, "Yier, how much did we spend today?" I said, "208 yuan for sportswear, 188 yuan for juicer, 396 yuan in total." my mother then asked, "what's the original price of these goods?" I said, "496 yuan." my mother said, "OK, that means that today we bought 496 yuan goods with 396 yuan, if you want to calculate the discount, Let's take a look at the proportion of the actual cost to the commodity price. Use 396 496, and you can calculate it with a calculator. "Once I press the calculator, it turns out that it's 79% off. I couldn't figure it out. Later, my mother told me. It turns out that only 200 yuan can be returned, so when I buy a juicer, I can't get a discount for 188 yuan, We enjoy the degree of discount compared with the business said is also discounted
It's true that buyers are not as good as sellers. The merchants have already made a good calculation in their hearts. There are mathematical problems behind the discount. I must pay attention to them in the future

What are the rules of length, area and volume units?

The length is ten times the difference
The area is 100 times the square of the length
Volume is the cube of length, 1000 times the difference