09-22-2016 03:41 PM
If you're using the stock keyboard, from the letter keyboard, to the left of the spacebar you'll see a ?, a 1, and a smiley all grouped together. Tap it, and the keyboard will change to numbers at the top and symbols on the rest of the keys.
The underscore is to the right of the $, and the dash is to the right of the &.
Hope this helps.