Answer
$280^{\circ}$
Work Step by Step
Subtract $360^{\circ}$ as many times as needed to obtain an angle with measure greater than $0^{\circ}$ but less than $360^{\circ}$.
$1000^{\circ}-(2\cdot360^{\circ})=280^{\circ}$
This is the angle of least positive measure that is coterminal with $1000^{\circ}$.