# Things with Math

Who doesn’t love Math? OK probably most people but it’s the foundation of programming so let’s have some fun!

## Binary Mathematics

This is a famous interview question: 'write a routine that adds two positive integers and do it without using mathematic operators'. Turns out you can do this using binary!

*14 minutes*

## Logical Negation

We've covered how to add binary numbers together, but how do you subtract them? For that, you need a system for recognizing a number as negative and a few extra rules. Those rules are one's and two's complement.

*11 minutes*

## Encryption Basics

In this video we play around with cryptography and learn how to encrypt things in a very simple, basic way. We then ramp up our efforts quickliy, creating our own one-time pad and Diffie-Hellman secure key transmitter.

*21 minutes*

## Hashing and Asymmetric Encryption

In this video we dive into hashing algorithms, how they're used and what they're good (and not so good) for. We'll also dig into RSA, one of the most important pieces of software ever created.

*34 minutes*

## Lambda Calculus

Before their were computers or programming languages, Alonzo Church came up with a set of rules for working with functions, what he termed lambdas. These rules allow you to compute anything that can be computed.

*20 minutes*

## Big O Notation

No video with this one - just a post with lots of code for quick review. Understanding Big O has many real world benefits, aside from passing a technical interview. In this post I'll provide a cheat sheet and some real world examples.

## Dynamic Programming and Fibonnaci

Dynamic programming gives us a way to elegantly create algorithms for various problems and can greatly improve the way you solve problems in your daily work. It can also help you ace an interview.

*9 minutes*

## Calculating Prime Numbers

The use of prime numbers is everywhere in computer science... in fact you're using them right now to connect to this website, read your email and send text messages.

*5 minutes*