I have entered a formula into a text box to pull calculations from other text boxes, now i want to be able to also manually enter numbers into that text box with a formula. Can i do this?

You want to override the calculation. This can be done, but it's tricky. 

First, your calculation has to be a custom script that uses "event.value" to set the Total field value, and does not have any standard formatting.

Next. the "event.rc" property enables or overrides setting the calculation value. So the issue is, "how do you set and clear this value?"

The answer is to use the keystroke event to set an override indicator.

Add this code to the keystroke event.

if(event.willCommit) event.target.setOverride = (event.value !="");

And add this code to the top of your calculation script

event.rc = !event.target.setOverride

Entering any value into the total field will overrride the calculation,

Clearing the value from the total field will reset the override and allow the calculation to continue.