2/2×4+2/4×6+2/6×8+…… + 2 / 98 × 100 =? What is the simple calculation method?

2/2×4+2/4×6+2/6×8+…… + 2 / 98 × 100 =? What is the simple calculation method?

2/2×4+2/4×6+2/6×8+…… +2/98×100=(1/2-1/4)+(1/4-1/6)+(1/6-1/8)+…… +(1/98-1/100)=1/2-1/100=49/100