Sum values from IF function

Hello! This is my first question in this forum.

I have searched through other questions but nothing quite matches what I am trying to do:

SUM a row of values which are calculated using an IF function:

I have assigned values to each selection in a drop down list, (I have done this using the following formula, which seems to be working - i.e: the required value is going into the cell I require) =IF(ISBLANK(Monday!H2),"0","10")
I have also tried: =IF(ISTEXT(Monday!H3),"10","0")

So basically on a Monday, I want to be able to select a meal that my customer has ordered, and for it to say "$10.00" on the invoicing sheet - if they haven't ordered then it is left blank - at the end of the week I want to be able to sum all the weekdays to be able to print out a weekly invoice, but the SUM function doesn't seem to work on the values that are showing up as a result of the IF formula.

My head hurts! Can anyone help me or point me in the direction of a relevant help article? Many thanks.

Originally Posted by sktneer

Please upload a sample workbook with enough sample data in it.

Book1.xlsx

The problem is summing the row on the weekly totals tab.
Thank you

Yes thank you!! It works, you lifesaver!!