M3.7.7 For the adult
Working out chances
A dice has six faces. How do I work out the chance of an even number?
What this chapter teaches
When every outcome is equally likely, probability = outcomes that count ÷ all outcomes. The chance that something does not happen is 1 take away the chance that it does.
Three questions to ask
There is no one right wording. Listen for the idea.
- How many outcomes does a dice have, and how many are even?
- If the chance of rain is 1/4, what is the chance of no rain?
- Why are HT and TH two different outcomes when you toss two coins?
After the chapter, the learner can
- Find a probability when all outcomes are equally likely
- Find the chance that something does not happen
What they copy into their notebook
Probability = outcomes that count ÷ all outcomes, when every outcome is equally likely. The chance of "not" is 1 take away the chance. Two coins have 4 outcomes: HH, HT, TH, TT.