Math for ages 8+
Simple probability ideas using jars, balls, and easy conversions.
Keep it simple: “out of 100” is usually easiest to understand.
Risk math (explained like you are 8)
Imagine a big jar with 100 balls. If 1 ball is red and 99 are blue, then the chance of getting a red ball is: 1 out of 100. That is the same as 1%.
Percent
1% means 1 out of 100.
10% means 10 out of 100.
1 in N
1 in 10 means 10%.
1 in 1,000 means 0.1%.
Per year
If something has a 1% risk each year, it does not mean 1% for your whole life.
Two helpful questions
- How often? (chance)
- How bad? (impact)
If you ride a bike without a helmet, you might fall sometimes (chance). A helmet makes the head injury less bad (impact). So the helmet reduces risk even if the chance of falling is the same.
Practice
Note: real-world risks often change with age, health, and where you live. This page is just for the math idea.