7200÷800= , 0.17+0.6= ,0.83-0.6=17×300=, 0.98-0.09=, 0.2+0.78=600×700=, 10.2+0.02=, 0.15+0.7=670+250= ,10.2+0.2= ,9.2-6=8500÷500= ;
3.2-3.2= ;
3.2-0.32= ;
2+2.8=380-290= ,0.35+0.5=, 0.35+0.63=3500÷70= ;
3.8+0.38=7500÷250=, 3.8+1= ,0.95-0.05=450+780= ;
3.1+0.3= ;
3+0.3=630÷9= ;