- Square roots of negatives
- Multiplying imaginary numbers
- Powers of i
- The parts of a + bi
- Real, imaginary or complex
- Plotting and conjugates
- Adding complex numbers
- Subtracting complex numbers
- Sums on the plane, and unknowns
- A number times a complex number
- Two complex numbers
- Conjugates and division
- Solving by square roots
- The quadratic formula
- Real or complex, and checking
- Unlocks after
- Opens up