You can change a dimension in a part, sketch, assembly, or drawing in the Modify dialog box.
- Double-click a dimension.The Modify dialog box appears. 
- Change the dimension value with the arrows, thumbwheel   , mouse wheel, or by typing in the dimension box. , mouse wheel, or by typing in the dimension box.The Modify dialog box displays a slider     instead of a thumbwheel when the numeric value is bounded, such as an angle that must be greater than 0 and less than 90 degrees. 
 | Up arrow,  Thumbwheel/Slider right, Mouse wheel up | Increases value by length increment set in Spin Box Increments. |  | Down arrow,  Thumbwheel/Slider left, Mouse wheel down | Decreases value by length increment set in Spin Box Increments. |  | Ctrl + Arrow or Ctrl + Thumbwheel/Slider or Ctrl + Mouse wheel | Increases/decreases length increment by 10 times the length increment set in Spin Box Increments. |  | Alt + Arrow or Alt + Thumbwheel/Slider or Alt + Mouse wheel | Increases/decreases length increment by the length increment set in Spin Box Increments divided by 10. |  
 
You can use the dimension box as a calculator by entering values and arithmetic symbols directly. You can also assign units of measurement to a value by using the type-ahead list or by typing the unit directly.  
- Choose from:
 
- Use the buttons as follows: