Adding Numbers That Have Text In Same Field?

I am working on making a time sheet log that will have employee name, 7 rows for days of the week and a row for total hours worked. each cell will either be blank in that row because employee has not worked that day or it will have numerical hours and the place the employee worked. We have many different job sites so text is subject to change. For example Monday employee 1 worked 8 hours at MRCR, so cell would state 8 MRCR Tuesday did not work so left blank. Wednesday worked 8 hours at CCR so will be 8 CCR. Thursday worked 8 hours at CU. so 8 CU in cell. Friday Saturday and Sunday left blank. How do i add create a formula that would be standard formula for each week for employee that would add numbers and omit text as well as ignore blank cells from week to week as the employee schedule changes.