9.9+19.9+199.9,用简便算法计算.五年级上口算,心算,天天练.39页,求答案.

2024-11-19 17:51:15
推荐回答(1个)
回答1:

9.9+19.9+199.9 = (10-0.1)+(20-0.1)+(200-0.1)=10+20+200-0.3=230-0.3=229.7