The basic idea is to roll cubes with numbers and mathematical functions on them. Two or more numbers can be combined to form multiple digit numbers. The players race to form a valid equation with some or all of the their cubes. He calls "TUF" and starts a 3 minute timer. If another player forms an equation with more cubes, he starts a 2 minute timer and calls "TUFFER". Further equations called out as "TUFFEST", "MORE TUFFEST", etc. and start 1 minute timer. When the last timer runs out, all players score for their best valid equation, but the player who makes the TUFFEST call scores double.

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