Slate's election scoreboard lists 1611 for Clinton and 1480 for Obama - these numbers include superdelegates. Slate's delegate calculator does not:

The calculator does not incorporate superdelegates into its calculations. Superdelegates are unpledged and uncommitted and therefore can change their endorsements and convention votes at any time. As a result, we've simply noted at the bottom of the calculator how many superdelegates the leading candidate needs to win the nomination in a given scenario.

Also, the election scorecard is basing its count on CNN's delegate count, with some adjustments. CNN currently has it 1622 for Obama to 1485 for Clinton - as opposed to the scorecard's 1611 to 1480; meaning they're showing 11 fewer delegates for Obama and only 5 fewer for Clinton as compared to CNN's totals. By your logic, Slate's in the bag for Hillary!