You can manually adjust the scale on the TI-Nspire Graphs page. By default, the axes tic labels are shown on the coordinate plane in close proximity to the origin. These can be accessed by pressing [MENU]→Window/Zoom→Window Settings.
Press [TAB] to navigate to XScale. The default setting is Auto. While the word is highlighted, type the scale that you would like to set for the x-axis. Repeat for the y-axis, and press [ENTER] twice to put the change into effect.
The scale can also be changed manually on the Graphs page: Move the cursor to one of the axes tic labels (located near the origin). Press [CLICK] twice to edit the current tic label. Change the value for the tic label and press [ENTER] to put the change into effect. Your scale changes remain in effect until one of the zoom tools is used.
The tic labels can be set to fractions. TI-Nspire CAS will even display irrational numbers like
For example, if you graph f(x)=sin(x), you might want to change the tic label on the x-axis to
You may be surprised to find out that it will display as the exact fraction,
