复选框选中jquery时更新总和

Here: https://jsfiddle.net/justeric/AWC4U/4/ checking a box will sum all entries in the textfield column and subtract that sum from 100, then it will place the difference in the corresponding textfield. So if 20 is the sum of all entries in the textfield column, checking a checkbox will result in 80 (100-20) being populated in the corresponding textfield. This feature works correctly but here's my problem: ch