Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 90

All fractions can be changed to decimals. In Chapter 1, you are told that rational numbers have decimals that can be written exactly as fractions. The decimal forms of rational numbers either end (terminate) or repeat in a pattern.

To change a fraction to a decimal, just divide the top by the bottom.

Q. Write as a decimal.

A. becomes and so .

Q. Write as a decimal.

A. becomes and so . The division never ends, so the three dots (ellipses) tell you that the pattern repeats forever.

If the division doesn’t come out evenly, you can either show the repeating digits or stop after a certain number of decimal places and round off. Another way to show repeating digits is to draw a bar over the digits that repeat. So can be written as .