When you’re writing in a rush, it’s easy for “out” to become “our” or “if” to become “it.” But another typo that’s more than just a slip of the fingers is mistaking “too” for “two.”
Of course, there’s no better typo defense than proofreading. You’re likely to catch that errant addition (too) or that wayward extra (two) when you really meant the opposite.
But if you still get stuck, think of it this way:
“Two” is spelled with a “double-u,” and double means one-two.
“Too” is spelled with an additional “o,” and that indicates an addition of some kind, as in “I want to go, too!” (in addition to the others).
ChanteSez.com 