0-1+2-3+4-5+6-7+8-9+10-.-99+100 0.1+0.3+0.5+0.7+0.9+0.11+0.13+.+0.97+0.99

0-1+2-3+4-5+6-7+8-9+10-.-99+100 0.1+0.3+0.5+0.7+0.9+0.11+0.13+.+0.97+0.99

0-1 + 2-3 + 4-5 + 6-7 + 8-9 + 10 -. - 99 + 100 original formula = (2-1) + (4-3) + (100-99) = 1 × 50 = 500.1 + 0.3 + 0.5 + 0.7 + 0.9 + 0.11 + 0.13 +. + 0.97 + 0.99 expand them by 100 times 25 * (10 + 99) = 2725 reduce them by 100 times 27.25 if you are right, this is the correct answer