What are bounds?

• Bounds are the smallest – the?Lower Bound (LB)?– and largest – the?Upper Bound (UB)?– numbers that a?rounded?number can lie between

How do we find bounds?

• The basic rule is “Half Up, Half Down”
• More formally:
  • UPPER BOUND – add on half the degree of accuracy
  • LOWER BOUND – take off half the degree of accuracy
  • ERROR INTERVAL: LB ≤?x?< UB

   

Calculations using bounds

• Find bounds before calculating and then:
  • For FRACTIONS/DIVISION:UB = UB ÷ LB?and

    LB = LB ÷ UB

  • Otherwise: 

    UB = UB × UB?etc.

Worked Example

轉載自savemyexam