积少成多（積少成多）　

◎ 积少成多 jīshǎo-chéngduō

[many a little makes a mickle;from small increments comes abundance;little will grow to much;penny and penny laid up will be many] 积累少数而渐成多数

其实一个人做一把刀,一个杓子,是有限得很;然而积少成多,这笔帐就难算了,何况更是历年如此呢。亦作积小成大。——清· 吴趼人《二十年目睹之怪现状》