probability · Year 6 · AC9M6P01
The probability scale from 0 to 1
Probability goes from 0 (impossible) on the left to 1 (certain) on the right, with one half in the middle. If the scale is split into equal steps, count steps from 0: 3 steps of 4 is 3/4. The same position can be written as a decimal, so 7 steps of 10 is 0.7 and 1/4 is 0.25. To place an event, count the outcomes where it happens out of all the equally likely outcomes, then find that point.
Sample questions
The arrow points to a probability on the scale. What probability does it show? Write it as a fraction.
- The scale from 0 to 1 is split into 5 equal steps.
- The arrow is 1 step from 0.
- Each step is 1/5, so the arrow shows 1/5.
Answer: 1/5
The arrow points to a probability on the scale. What probability does it show? Write it as a fraction.
- The scale from 0 to 1 is split into 4 equal steps.
- The arrow is 1 step from 0.
- Each step is 1/4, so the arrow shows 1/4.
Answer: 1/4
The arrow points to a probability on the scale. What probability does it show? Write it as a fraction.
- The scale from 0 to 1 is split into 4 equal steps.
- The arrow is 3 steps from 0.
- Each step is 1/4, so the arrow shows 3/4.
Answer: 3/4