My mother passed away in June and left an annuity to her 5 grandchildren ages 10 and under. The annuity is an IRA so they each have to take distribution of it and pay taxe.

Does each grandchild file an individual return with this as their sole income for 2013?

Can they still be claimed on their parents returns as dependents. What rate are they taxed at?

How can I calculate what they will owe in taxes?

Can they take the standard deduction if they are claimed as dependents?

Thanks.