Day 05 - Worksheet 4C
We're only a few days away from the test on the factor-label method. It's such an essential skill for engineering that you will be required to use this method to solve problems for the remainder of your time in STEM, so the sooner you can master it, the better!
Today we're adding the concept of percentages to our calculations. There are two tricks to percentages and the factor-label method:
- knowing that "per" means "divide by" and "cent" means "100."
- knowing whether your answer needs to be bigger or smaller than your starting amount
Thus, 64% is written as 64/100, and if you want 64% of 300, your answer needs to be smaller than your starting point (which means you will multiply 300 by 64 and divide by 100), but if you know that 300 is 64% of some total quantity, the total quantity will be bigger than the 300 (which means you will multiply 300 by 100 and divide by 64). It sounds confusing when written out like this, but once I demonstrate it on the board it should make more sense.
Use this knowledge to start tackling Worksheet 4C, which is due by the end of the bell tomorrow (or it becomes homework preparatory to the test on Wednesday!).
