一个圆柱体的高减少2厘米,表面积就减少12.56平方厘米,如果这时高比原来减少,那么原来这个圆柱体的体积是 立方厘米.
科技书的本数比文艺书少,把 看作单位“1”,科技书的本数是文艺书的 .
涂一涂,算一算,填一填. (1) + = + = (2) ﹣ = ﹣ = .
我会填. (1) = = ; (2) =﹣ = .
在横线里填上合适的数. (1)+ = (2)+ =1 (3)﹣ = (4) ﹣=0.
看图写算式. (1) + + = . × = (2) + = = . × = = (3) + + + = . × = .