Multiple and sub-multiples of units

• What is the purpose of stating units in measurements?

  To clarify the quantity being measured and its accuracy
• What is the SI unit system?

  It is the internationally agreed system of measurements known as Système Internationale d'Unités
• How can large or small numbers be expressed conveniently in science?

  By using standard form
• What does standard form involve?

  Writing a number as a value between 1 and 10 multiplied by a power of ten
• How is the distance from the Sun to Pluto expressed in standard form?

  From 4,400,000,000,000 m to 7,300,000,000,000 m is expressed as $4.4 \times 10^{12} \text{ m}$ to $7.3 \times 10^{12} \text{ m}$
• What are unit prefixes used for in measurements?

  • To reduce the length of numerical measurements
  • Examples of prefixes:
  • 1 km = 1,000 m
  • 1 Tm = 1,000,000,000,000 m
  • 1 Gm = 1,000,000,000 m
  • 1 Mm = 1,000,000 m
  • 1 km = 1,000 m
  • 1 cm = 0.01 m
  • 1 mm = 0.001 m
  • 1 μm = 0.000001 m
  • 1 nm = 0.000000001 m
• How can the distance from the Sun to Pluto be expressed using unit prefixes?

  As 4.4 Tm to 7.3 Tm
• Which is larger: 360 kV or 3.6 MV?

  1. 6 MV is larger
• How do you convert 360 kV to volts?

  360 kV = 360,000 volts
• How do you convert 3.6 MV to volts?

  1. 6 MV = 3,600,000 volts
• What are the key concepts of unit prefixes in measurements?

  • Tera- (T): $10^{12}$
  • Giga- (G): $10^{9}$
  • Mega- (M): $10^{6}$
  • Kilo- (k): $10^{3}$
  • Centi- (c): $10^{-2}$
  • Milli- (m): $10^{-3}$
  • Micro- (μ): $10^{-6}$
  • Nano- (n): $10^{-9}$