0.9+0.42=53.9﹣5.9=5.4+4.6×5=0.25×4÷0.25×4=4÷3.3=(商用循环小数表示)
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=