The best arithmetic game ever invented by accident
Cribbage
Three hundred years old and still the fastest way to make a child fluent in number bonds to fifteen. Every hand is a search for combinations that add to 15, and the counting never stops.
- Players
- 2
- Time
- 20 to 30 minutes
- Ages
- 9 and up
What you need
- A standard deck of 52 cards
- A cribbage board, or a pencil and paper
How to play
- Deal six cards each. Deal six cards to each player. Both players choose two cards to put face down in a pile called the crib. The crib belongs to the dealer and is scored at the end of the hand.
- Cut the starter. The non-dealer cuts the deck and the top card of the bottom half is turned face up. This is the starter, and it counts as part of everybody's hand when the scoring comes.
- Play to thirty-one. Taking turns, lay one card at a time face up in front of you and say the running total out loud. Picture cards count ten, aces count one. Nobody may take the total past 31. If you cannot play without going over, say 'go' and your opponent keeps laying cards until they cannot either.
- Score as you play. Landing the total exactly on 15 scores 2. Landing it exactly on 31 scores 2. Matching the card just played scores 2 for a pair, 6 for a third, 12 for a fourth. Three or more cards in a run, in any order, score one for each card.
- Count the hands. When all cards are played, each player counts their four cards plus the starter. Every combination adding to exactly 15 scores 2 — and combinations may overlap, so one card can be part of several. Pairs score 2, runs score one per card, four of the same suit score 4, five score 5.
- Count the crib last. The dealer counts the crib the same way. Then the deal passes. First to 121 wins.
The maths in it
Fifteens are the heart of it. A hand with 7, 8, 6, 9 has to be searched for every pair and triple that reaches fifteen, and a child who plays for a fortnight stops searching and starts seeing. The pegging phase is a running total held in the head under mild pressure, which is exactly the skill a worksheet cannot drill.
Making it fit the child
Easier: Play to 61 instead of 121, and let a younger child use fingers or counters for the running total. Drop the crib entirely for the first few games — the hand scoring alone is plenty.
Harder: Play the crib as it is meant to be played: discard to it deliberately, keeping the dealer's crib strong and starving the opponent's. That turns every discard into a small optimisation problem.