Yahtzee Trainer
You play Yahtzee and learn to work out chances as fractions and percentages. In explain mode the coach shows you the chances with every throw and how they come about. In the game with joker you play yourself and ask for help when you need it. In the plain game you collect points for the high-score list. For grades 7 and 8, when you are already good with fractions and percentages.
Choose
- Explain mode The coach shows the chances and the calculation with every throw.
- Game with joker You play yourself. The joker helps you find the calculation yourself.
- Plain game Play without help and collect points for the high-score list.
How it works
- Choose whether you play the upper half (6 rounds) or the whole sheet (13 rounds).
- Roll up to three times. Tap the dice you want to keep. The space bar rolls, the keys 1 to 5 hold a die.
- Enter the result in a field of the score sheet. Escape pauses the game.
- The trainer works out one turn: at most two more throws and one field. It does not plan the whole game.
What you learn
- I can name all possible results of a die.
- I can give the chance of a certain number as a fraction and as a percentage.
- I can work out the chance that two dice both show the number I want.
- I can work out how likely it is that at least one wanted number is among several dice in one throw.
- I can compare the chance of a wanted result after the first and after the second re-throw.
- I can explain why keeping dice improves the chance.
- I can compare two possible moves by their chances.
- I can connect the points a field brings with the chance of getting them.
- I can explain which dice I keep and which field I choose.
How the trainer works it out
With one die the chance of a certain number is 1/6, of any other number 5/6. With several dice the trainer draws a tree: each branch shows its chance, the end of each way the product. The ways with a hit are added up. Or you take the opposite: 1 minus the chance that no hit ever comes.
The trainer compares which field is worth it with what the field brings on average. Those are approximate values, not a proven strategy.