4.2+ x=6 3x- x=2.7
3.14×7=
25.12÷3.14 =
25×50%=
5.5÷50%=
×= 6×= 1÷= ×=
÷= += 35÷= ×21=
100×25%=
÷40%=
1-72%=
36%+64%=
80×(1+25%)=
60÷(1-40%)=
45×(1-20%)=
72÷(1+20%)=
①
②
③
④(1+25%)x=12.5
4人有几只手?
8只手上共有几根手指?
口诀: