A bushel is nominally a dry volume measure, but the futures market treats it as a fixed weight that differs by commodity because grains have different densities. Every CBOT grain contract is 5,000 bushels, so the tonnage varies: corn is 127 tonnes, wheat and soybeans about 136.
Prices are quoted in cents per bushel and, confusingly, in eighths of a cent displayed with a trailing digit. 445'2 means 445 and 2/8 cents, or $4.4525 per bushel.
Example: corn at 445'0 is $4.45 x 5,000 = $22,250 per contract. The minimum tick of a quarter cent is $12.50. Converting to tonnes, $4.45 x 39.368 bushels per tonne = $175.19 per tonne, which is how the same grain is quoted in Europe.
Related: corn-futures, wheat-futures, soybean-futures, contract-multiplier, tick-size