Numeric Keypad Keys

The numeric keypad keys / * - + are bound to these commands by default:

Key

Command

/

Scroll Half Page Up

*

Scroll Half Page Down

-

Function Up

+

Function Down

If you want those keys to function normally by just inserting the character on the key top, then you need to unassign those keys from the commands.

Use the Options > Key Assignments dialog box to find those commands and delete the key assignments for each of them. When the key assignments are removed from those keys, they will function normally.