口算.5+4= 5-3= 3+0=8+7= 9+7= 7-7=3+5= 10-4= 9-8=7-2= 7-6= 3+7=10-6= 9-6= 9-5=5-4= 8-3= 5+2=
14.8×6.3-6.3×6.5+8.3×3.7 18.1+(3-0.299÷0.23)×1
5.09-(0.09+1.23) 9.36-(4.36-3.5)
7.5-2.45+7.5+2.45 (-)×21+
2.5×(1.92÷0.3-5.9) 24.5-(7.58+)
45.55-(6.82+15.55) 34.52-17.87-12.23