3把钥匙3把锁,不知道哪把钥匙配哪把锁,最多试开 次可以保证打开3把锁.
根据乘法算式写出两道除法算式.×5= .
方框里藏着什么数字? ×70=420 560÷ =80 30× =270 360÷ =9 180÷ =3 340× =200.
(1)24× ﹣ ×5=95(2) ×36+35× ﹣ =140.
填一填8× =480 ×6=420 80×O= × =4900 ×3=120 ×6=3600 5× =250 × =5600.
填一填. × =600 × =1260.