1/2➕1/3=5/6
1/2➕1/3➕1/4=13/12=1➕1/12
1/2➕1/3➕1/4➕1/5=1➕17/60
1/2➕1/3➕1/4➕1/5➕1/6=1➕9/20
1/2➕1/3➕1/4➕1/5➕1/6➕1/7=1➕83/140