Free Science Lessons: Order of Magnitude

Key Concepts

• Order of Magnitude is used by scientists to compare the approximate sizes of different objects.
  • It represents how many times one value is bigger or smaller than another.
  • Every order of magnitude is 10 times greater than the previous one.

Examples

• An apple and an orange are around the same size, so they are of the same order of magnitude.
• A pineapple is about 10 times larger than a small lemon, making it one order of magnitude larger.
• A dog is approximately 100 times longer than a woodlouse, so it is two orders of magnitude larger.

Calculating Order of Magnitude

• To find the order of magnitude:
  • Count the number of zeros in the multiplication factor.
  • 10 times is one order of magnitude (one zero).
  • 100 times is two orders of magnitude (two zeros).
  • 1,000 times is three orders of magnitude (three zeros).

Practice Question

• Example: A fox is around 40 cm long, and a tick is about 0.4 cm long.
  • Calculate: 40 cm / 0.4 cm = 100 times
  • Therefore, the fox is two orders of magnitude longer than the tick.

Resources

• For more practice, refer to questions on orders of magnitude in the workbook available on the website.