7−1+12= 7-1+\frac{1}{2}= 7−1+21=
According to the order of operations rules, we solve the exercise from left to right:
7−1=6 7-1=6 7−1=6
6+12=612 6+\frac{1}{2}=6\frac{1}{2} 6+21=621
612 6\frac{1}{2} 621