Placing events on a probability scale from 0 (impossible) to 1 (certain), using fractions, decimals, or percentages.
Where your child meets this in real life: Understanding percentages in weather forecasts or betting odds
SEAGReady breaks probability scale into 3 steps, taught in order so each skill builds on the last.
Place events at the three key benchmark positions on the probability scale: 0 (impossible), 1/2 (even chance), and 1 (certain)
Place events at positions between the benchmarks using simple fractions (e.g., 1/6, 1/4, 3/4)
Express and recognise the same probability position as a fraction, decimal, or percentage
Three free sample questions from our probability scale course. Every question comes with a full explanation, and hints that guide without giving the answer away.
Oisin has a fair coin. He flips it once. Where should he place 'getting tails' on the probability scale?
Answer: B. 1/2 (even chance)
A fair coin can land on heads or tails. Both outcomes are equally likely. Equal chances = even chance. Even chance is at 1/2 on the probability scale. So 'getting tails' is at 1/2.
Stuck? Start here: Think about the possible outcomes when you flip a coin.
Conor rolls a fair 6-sided die. Where on the probability scale is 'rolling a 5'?
Answer: A. 1/6
A fair die has 6 equally likely outcomes: 1, 2, 3, 4, 5, 6. Only 1 outcome shows a 5. 1 out of 6 = 1/6. 1/6 is between 0 and 1/2 on the probability scale (unlikely). So 'rolling a 5' is at 1/6.
Stuck? Start here: How many different numbers could Conor roll?
The weather forecast says there is a 50% chance of rain in Derry. What is this as a fraction on the probability scale?
Answer: B. 1/2
50% means 50 out of 100. 50/100 can be simplified: 50 ÷ 50 = 1 100 ÷ 50 = 2 So 50% = 1/2 on the probability scale. This is even chance - in the middle of the scale.
Stuck? Start here: 50% means 50 out of 100.
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
Ciara has a fair coin. She is going to flip it once.
Where should she place 'getting heads' on the probability scale?
P(heads) = ?
Step 1 of 4
Ciara has a fair coin. She is going to flip it once.
Where should she place 'getting heads' on the probability scale?
Getting heads is at ½ (the middle) on the probability scale.
The key insight: The probability scale has three anchor points: 0 (impossible), ½ (even chance), and 1 (certain).
Watch out: Placing heads at 1 because I think it will happen. 1 means certain (it MUST happen). Heads might happen but tails might too.
These are the misconceptions we see most often in probability scale, including the ones our practice questions are specifically designed to catch.
Struggling with probability scale? The real gap is often in one of these earlier topics.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.