Notes on Order of Magnitude from Free Science Lessons

Introduction

• Objective: Understand and calculate the order of magnitude.
• Use order of magnitude to compare approximate sizes of objects.

Definition of Order of Magnitude

• Order of magnitude is used when comparing the approximate size of different objects.
• Example: An apple and an orange are around the same size, so they are around the same order of magnitude.

Calculating Order of Magnitude

• If one object is 10 times larger than another, it is one order of magnitude larger.
• Example:
  • Pineapple vs. Lemon: Pineapple is about 10 times larger than a lemon, equating to one order of magnitude larger.
  • Dog vs. Woodlouse: Dog is about 100 times longer than a woodlouse, which is two orders of magnitude.

Key Concept

• Each order of magnitude is 10 times greater than the previous one.
• Method: Count the number of zeros to determine the order of magnitude.
  • 10 times = 1 zero = 1 order of magnitude.
  • 100 times = 2 zeros = 2 orders of magnitude.
  • 1000 times = 3 zeros = 3 orders of magnitude.

Practical Example

• Problem: A fox is around 40 cm long, while a tick on the fox is around 0.4 cm long.
• Solution:
  • Divide 40 by 0.4 = 100 times longer.
  • Count zeros: 2 zeros = 2 orders of magnitude.

Practice Resources

• More practice questions available in the workbook.
• Workbook can be accessed via provided link.

Conclusion

• After understanding, you should be able to describe and perform calculations related to the order of magnitude.