Metric System Conversions

Mnemonic for Metric Prefixes

• Mnemonic Sentence: "King Henry died by drinking chocolate milk"
• Prefix Breakdown:
  • K (King): Kilo ($1000 \times$ base unit)
  • H (Henry): Hecto
  • D (Died): Deca ($\text{da}$)
  • B (By): Base unit (grams [$\text{g}$], liters [$\text{L}$], or meters [$\text{m}$])
  • D (Drinking): Deci ($\text{d}$)
  • C (Chocolate): Centi ($\text{c}$)
  • M (Milk): Milli ($\text{m}$) ($1000 \times$ smaller than base unit)

Decimal Movement Strategy

• Identify the starting prefix position and the target prefix position on the metric scale.
• Count the number of places and note the direction (left or right) between the two positions.
• Move the decimal point in the original number by that exact number of places and direction.
• Drop unnecessary leading zeros after moving the decimal point.

Conversion Examples

• $56.3\,\text{cm} = 563\,\text{mm}$ (moved $1$ place to the right)
• $356.8\,\text{mL} = 0.3568\,\text{L}$ (moved $3$ places to the left)
• $673.1\,\text{g} = 0.6731\,\text{kg}$ (moved $3$ places to the left)
• $0.673\,\text{m} = 67.3\,\text{cm}$ (moved $2$ places to the right; leading zero is dropped)

Whole Numbers

• For any whole number without a visible decimal, the decimal point is located directly behind the last digit.
• Example: $47\,\text{m} = 4700\,\text{cm}$ (moved decimal $2$ places to the right from $47.0$).