问题 解答题 口算题784+516=9.9÷0.11=17×2.1=0.66+3.34=0.45×0.6=15-16=58÷2.5=45÷2÷45=22.5-9.9= 答案 784+516=1300,9.9÷0.11=90,17×2.1=0.3,0.66+3.34=4,0.45×0.6=0.27,15-16=130,58÷2.5=14,45÷2÷45=12,22.5-9.9=12.6.