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- Create a new hidden value by clicking on the in the Question Bar'Add Question' followed by Hidden Value from the question tree.
- Change the Question ID to "edd"
- Click on "Edit" next to the Calculate Condition box
- Drag the question "Date of Last Menstrual Period" over to the Expression Editor (Advanced) box until you see the green check mark, and then release
- Write a "+" because we want to add something to this date
- Type "274." Your total expression should look like this:
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