三(1)班教室的黑板在教室的西面,那么老师背对黑板讲课时面向( )面.
对算式80.41-(6.28+25.41)-3.72计算方法简便的是( )A.80.41-25.41-(6.28+3.72) B.80.41-25.41-6.28-3.72
对算式6.67+0.49-3.67计算方法简便的是( )A.6.67-3.67+0.49B.6.67+(0.47-3.67)
运用加法运算定律,使(8.28+2.69)+4.72运算简便的计算过程是( )A.(8.28+2.69)+4.72 =(8.28+4.72)+2.69 =13+2.69 =15.69B.(8.28+2.69)+4.72 =8.28+2.69+4.72 =10.97+4.72 =15.69C.(8.28+2.69)+4.72 =2.69+8.28+4.72 =2.69+13 =15.69
0.75+0.875+1.25+0.125=(0.75+1.25)+(0.875+0.125)应用的是( )A.加法交换律 B.加法结合律 C.加法交换律和结合律
对算式327-2.63-0.37计算方法简便的是( )A.327-(2.63+0.37) B.327-0.37-2.63