问题
解答题
1.89+2.25+2.75=1.89+(______+______),这是根据______.
答案
加法结合律字母表达式为:a+b+c=a+(b+c),
1.89+2.25+2.75=1.89+( 2.25+2.75)符合加法结合律,
故答案为:2.25,2.75,加法结合律.
1.89+2.25+2.75=1.89+(______+______),这是根据______.
加法结合律字母表达式为:a+b+c=a+(b+c),
1.89+2.25+2.75=1.89+( 2.25+2.75)符合加法结合律,
故答案为:2.25,2.75,加法结合律.