列竖式计算。319+496=162+959=
137+238-279=289+234-271=
234+123-235=234+321-136=
11+5+1= 12+7-1=
12-3-5= 19-2-4= 15-7-4=18-6-8= 17-6-9= 19-9-8
16-1+2= 17-2+4= 8+9-7= 17-9+2=12+3-7= 14+6-2= 10+4-8= 10-7+1=