Spinner trials
Build a spinner with two, four, six or eight wedges and adjust the expected percentage for each outcome.
Free maths tool
Probability lab tool
A free probability lab for running spinner, coin flip and bag-draw trials, then comparing expected chances with tally results.
Coin and bag draws
Run coin flips or bag draws with editable counter counts to compare equal and unequal chances.
Tallies and percent
See each outcome as a tally, count, total and collected percentage as trials build up.
Graph maker link
Send the collected results straight to the graph maker when the class is ready to display the data.
What the tool does
The probability lab tool gives teachers and students a quick way to run chance experiments and compare expected outcomes with collected results.
- run spinner, coin flip and bag-draw trials
- set spinner wedges and percentage weights
- change the number of coloured counters in the bag
- run trials one at a time or in batches
- copy the results table or open the data in the graph maker
How teachers use it
Open it on a classroom screen when students need to predict, test and discuss chance outcomes.
- start with a prediction before running any trials
- run a small batch and compare the results with the expected chance
- change one spinner wedge or bag count and ask what should change
- send results to the graph maker for a shared data display
Why it is useful
Probability is easier to discuss when students can see that short runs can be uneven while larger samples often move closer to the expected chance.
- makes chance visible through repeated trials
- connects likelihood language to counts, tallies and percentages
- supports classroom discussion before scored chance and probability practice
Frequently Asked Questions
Is the probability lab tool free?
Yes. Teachers, students and families can open the probability lab tool in a browser for free.
What experiments are included?
The tool includes spinner trials, coin flips and bag draws, with tallies and collected percentages.
Can the spinner or bag be changed?
Yes. Teachers and students can adjust spinner percentages and change the number of coloured counters in the bag.
Does it score student answers?
No. It is an open modelling tool, not a scored practice activity or student-tracking page.