在混合运算时,规定按“先乘除,后加减”的顺序来进行计算的。要想先加减的话还得多加上括号。但你想过没有,为什么不是反着来,先加减后乘除呀。我们可是先学加减,后学的乘除。让我们从日常生活中去寻找线索吧。看看下面几个情况:1、你和妈妈去菜场买菜,买了2捆青菜,3斤鱼,青菜一 In mixed operation, the provisions of the “first by the addition and subtraction, after the addition and subtraction,” the order to be calculated. To add or subtract, you have to add more brackets. But you thought no, why not the reverse, the first addition and subtraction multiplication ah. But we first learn addition and subtraction, multiplication and division after school. Let’s look for clues in everyday life. Take a look at the following situations: 1, you and your mother go to the farms to buy food, bought 2 bundles of vegetables, 3 pounds of fish, vegetables a