Cutting tablecloths

Imagine a square piece of cloth 1 meter by 1 meter that could be altered to make a tablecloth for a rectangular table.

You could cur off a strip 20% of the way along the square, rotate it, and attach it to the other edge to make a rectangle. There would be a little bit of cloth left over!

· The purple square is the original tablecloth.

· The blue rectangle is the new tablecloth.

· The red piece shows the cloth that is left over.

Look at the diagram

· What percentage of the original cloth has been used to make the new tablecloth? Instead of cutting off a 20% strip, you could cut a 10% strip, or a 15% strip, or a different percentage.

Choose some percentages to try. For each example, think about the following questions:

· What percentage of the original tablecloth is used to make the new tablecloth?

· What percentage of the original tablecloth is wasted?

· Is there a quick way to work out the percentage of cloth used and wasted, if you know what percentage strip was cut off?

Then answer these questions.

· To make a rectangular tablecloth in this way, with an area of 75% of the original cloth, what percentage strip would you need to cut off?

· To make a rectangular tablecloth in this way, with an area 50% of the original cloth, what percentage strip would you need to cut off?