# Number Line Fractions

*Tuesday 12/9/08*

### Do-now: Marks and Spaces

Each mark on a number line stands for a particular number. These numbers always count up as you move to the right. They don't always count up in ones, but they do usually count up in multiples of some number. The number value of a mark is written directly **above** the mark.

Sometimes it is useful to make note of how long the spaces between marks are. To do this, we write the length of the space **under** the **middle** of the space. So, for example, the number line above is correct; the length each space is labeled with agrees with the difference between the marks.- Fill in numbers for all the spaces and marks that are blank on this number line.

- Fill in numbers for all the spaces and marks that are blank on this number line.

- Fill in numbers for all the spaces and marks that are blank on this number line.

- Fill in numbers for all the spaces and marks that are blank on this number line.

- Fill in numbers for all the spaces and marks that are blank on this number line.

- Fill in numbers for all the spaces and marks that are blank on this number line.

### Checking number lines

- The
**space lengths** on this number line are all correct, but some of the **mark numbers** are not. Fix any mark numbers that are wrong.

- The
**space lengths** on this number line are all correct, but some of the **mark numbers** are not. Fix any mark numbers that are wrong.

- The
**mark numbers** on this number line are all correct, but some of the **space lengths** are not. Fix any space lengths that are wrong.

- The
**mark numbers** on this number line are all correct, but some of the **space lengths** are not. Fix any space lengths that are wrong.

### Number lines in science

- What are some examples of number lines we use in science?

- Why can't all number lines just be marked off in ones, to make them easy to read?