Will it happen?
Some things are sure to happen, some might happen, and some can’t happen at all. Talking about chance means talking about how likely something is.
Words for chance
| Word | Meaning | Example |
|---|---|---|
| Certain | Will definitely happen | The sun will rise tomorrow. |
| Likely | Will probably happen | It will be cold in January in Canada. |
| Maybe / even chance | Could go either way | A coin will land on heads. |
| Unlikely | Probably won’t happen | It will snow in July in Toronto. |
| Impossible | Can never happen | A dog will fly to the moon by itself. |
A chance line
We can place events on a line from impossible to certain:
impossible — unlikely — even chance — likely — certain
The further right, the more likely something is.
Thinking about likelihood with objects
Imagine a bag of marbles:
| Bag | Pick a red marble? |
|---|---|
| 10 red marbles | Certain |
| 8 red, 2 blue | Likely |
| 5 red, 5 blue | Even chance |
| 2 red, 8 blue | Unlikely |
| 10 blue marbles | Impossible |
The more red marbles in the bag, the higher the likelihood of picking red.
Chance is not a promise
"Likely" doesn’t mean "will happen". Even if a bag has 9 red marbles and 1 blue, you might still pick blue. Unlikely things do happen sometimes; they just don’t happen often.
Worked examples
Example 1: Is it certain, likely, unlikely or impossible that you will roll a 7 on a normal 6-sided die?
A die only has 1 to 6: impossible.
Example 2: A spinner is mostly green with a small yellow part. Where will it most likely land?
On green, because it has the bigger space.
Example 3: It is cloudy and dark. Is rain likely or unlikely?
Likely (but not certain).
Common mistakes
- Mixing up "unlikely" and "impossible". Unlikely things can still happen.
- Thinking "likely" means "certain".
- Ignoring how many of each item there are when thinking about chance.
Try it yourself
- Is it certain, likely, unlikely or impossible: a cat will meow today?
- A bag has 10 green blocks. What is the chance of picking a green block?
- A spinner has 3 red parts and 1 blue part, all the same size. Which colour is more likely?
- Name something impossible.
Answers: 1) likely 2) certain 3) red 4) e.g. a fish riding a bicycle
Quick recap
- Chance is how likely something is to happen.
- Use certain, likely, unlikely and impossible.
- Unlikely things can happen; impossible things cannot.