When the amount was being entered if you do not have any additional capital gain apart from foreign capital gain, you should enter the same amount in total capital gain. However, if you have any additional capital gain, then you have to enter the total of both foreign capital gain and other capital gains into BOX: - 21 which is right after foreign capital gain.
For more information on T3 go to this page of the Canada Revenue Agency: -
T3 Statement of Trust Income Allocations and Designations (slip)Thank you for choosing TurboTax.