blackpenredpen

blackpenredpen is a maths channel made by a maths teacher called Steve, who writes with a black pen and a red pen on a whiteboard. He has made thousands of tutorials across his channels.

Videos are worked examples, solved live on the board. Topics include algebra, complex numbers, calculus, integration and fun problems that seem impossible at first. He is known for long marathon videos that work through 100 problems in one sitting. The aim is to show that hard maths gets easier with practice. His enthusiasm is infectious, and he often shows more than one method so viewers can compare approaches.

Some highlights include:

An exploration of whether the equation x to the power x equals 0 has a solution.

Solving x to the power 5 equals 1, which leads into complex numbers and roots of unity.

Why the volume of a cone is one third of a cylinder, explained with calculus.

blackpenredpen has over 1.4 million subscribers.

Strong maths is the foundation of every engineering degree. Calculus and complex numbers in particular are used all the time in electrical, mechanical and civil engineering. This channel is a good way to practise those skills beyond the classroom. It suits students taking A level maths or further maths who want to feel more confident before university.