Janna is measuring the dimensions of her bedroom to determine how much paint she should buy for the walls. If her measuring tape has increments of 0.01 meter, which of the following could be the length of one wall with the correct number of significant digits?

You always estimate between the markings. If the markings are at the hundredths place, then you estimate the thousandths. She saw that the length she was measuring was just a little beyond the 4.83 line, so she guessed it was 4.831 m. (If you are trying to measure a room for paint purchase, you are wasting your time if you try to get a precision of ±1 mm!)