Absolute Value
Students first learn absolute value in middle school as the distance from zero. So |5| = |-5| = 5. In high school, absolute value is combined with algebra and inequalities.
Many specifications can be written with absolute value such as an acceptable measurement within a certain range -- for example 4.75 Volts - 5.25 Volts could be the desired power supply voltage for a computer chip. This could be expressed as 5 +/- 0.25 Volts and could be written as |x - 5| is less than or equal to .25. By writing this with an absolute value, we take into account that the amount could be over or under by as much as .25 and still be within spec.
Coolmath Absolute Value
Absolute Value Inequalities on Purplemath
Solving Absolute Value Graphs on the Graphing Calculator
Data Sheet for 54LS74 Computer Chip |