问题 解答题 看谁算得对又快421×3=108×9=17×8=36×5=628×5=645×8=807×4=302×7=320×7= 答案 421×3=1263108×9=97217×8=13636×5=180628×5=3140645×8=5160807×4=3228302×7=2114320×7=2240