Sum until text

Hi im a newbie when it comes to formulas, Is there a way to sum a column up to a certain point then it stops?

___a______b
1 _______30
2 _______40
3 _______50
4 _______32
5 text 21
6 _______67
7 _______82

I need it to sum all of column B but only until row 5 when theres a text that shows up on column A. So it would be 30+40+50+32.
I need the formula to stop wherever somebody puts text in column A.