×16= × = 9× = × =
÷2= 12÷ = ÷ = ÷ =
24×=
5÷=
×=
×÷×=
÷=
1.21×=
1÷×=
4×=
25+0.075= +2.25= 20%+8= 4.2÷15%=
÷= 0×+
0.375÷0.375 3.14×π n+n×(n>0)
验算: