Line 3 of the Worksheet for Determining Support says, "Enter the amount on line 1 that was used for other purposes." It is asking for what amount of the funds shown on line 1 were used for purposes other than support.
In order to determine if you have provided more than half of a person's total support by comparing the amount you contributed to that person's support with the entire amount of support that person received from all sources. This includes support the person has provided from their own funds.
To figure if you have provided more than half of a person's support, you have to determine the total support provided for that person. Total support includes amounts spent to provide food, lodging, clothing, education, medical and dental care, recreation, transportation, and similar necessities.
The following items aren't included in total support.
1. Federal, state, and local income taxes paid by persons from their own income.
2. Social security and Medicare taxes paid by persons from their own income.
3. Life insurance premiums.
4. Funeral expenses.
5. Scholarships received by your child if your child is a student.
6. Survivors' and Dependents' Educational Assistance payments used for the support of the child who receives them
Click here for Worksheet for Determining Support
Click here for Dependents, Standard Deduction, and Filing Information