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

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

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

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

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

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

### Checking number lines

1. 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.

2. 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.

3. 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.

4. 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

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

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