This portion is taken from CHEM Fall 2024

Significant figures:

  • No zero → significant
  • Zero
    • Leading (before .) → non sig
    • Between → sig
    • Trailing (after non zero numbers) → is there a decimal?
      • Yes decimal → sig
      • No decimal → no sig

@@ Exact number: 

  • something you can count exactly → infinite numbers of sig figures
  • Conversion: example: 1 inch = 2.54cm exactly
  • Metric prefixes 2cm
  • Scientific notation: sig figure x10

Rounding:

  • Multiply/Dividing: can’t have more sig fig than original
  • Add/Minus: can’t have more fig after . than original