Figure

Math and relationships

Positive and negative values

Represent values above and below a reference and change a number’s sign.

A sign locates a value relative to a reference. Choose which direction is positive and keep that convention throughout the calculation. Changing a number’s sign and subtracting a number are separate actions.

Work above and below a reference

Use negative values below a chosen reference and positive values above it.

Choose your zero

For elevation, choose a reference level as zero. A point 2 ft below it is −2 ft. Moving up 5 ft puts you 3 ft above that same reference.

Try it · start 2 ft below zero

Use 2nd if Feet is above its key. ± changes the sign of your entry; − starts a subtraction.

  1. Start fresh

    Press Clear entry, then Clear entry, then Select length units.

  2. Starting elevation

    Press 2, then feet, then Second, then Change sign.
  1. Below the reference−2 feet 0 inches

Move up 5 ft

  1. Add the upward change

    Press Add, then 5, then feet, then Equals.
  1. Above the reference3 feet 0 inches

Also useful for

Drain and pipe elevations, grade changes, offsets from a layout line, and tracking gains or losses in stock or cost.

Remember

Keep the same zero and sign convention throughout. A negative result tells you the direction relative to that reference; it is not a negative physical length.

Change the sign

Change the sign of the displayed value.

Start a new calculation

  1. Press Clear entry, then Clear entry.

Calculate

  1. Number

    Press 2, then Second, then Change sign.
  1. Example result−2

Keep the guide beside your calculation.

These examples are built into Figure. Open Help while you calculate, then return to the same guide and reading position.

See Help in Figure →