Here’s an idea for way in the future, but something I think would be really cool. I posted this suggestion on excel.uservoice.com a while ago.
The idea would be to create a data type that lets you modify the value of a cell using a slider. So, you click on a cell containing this value, then a slider appears below or above the cell that lets you quickly change the value. If you didn’t limit it to integers, you could force it to be integers based on the choice of interval and min/max value.