# Work With the Number Line Contraption

## Work Time

# Work With the Number Line Contraption

Suppose you put the dot on a number and tossed it over the center; then, you put the dot at the place where it just landed, and tossed it over the center again.

- Where would the dot land?
- Write an expression for this action.

*INTERACTIVE*: Number Line Contraption

- Use the Number Line Contraption interactive to test what happens if you swing the lever twice.
- Use a negative sign to represent each swing of the lever.
- Use
*a*to represent any number.