■ What is Modular Arithmetic? | An introduction to the strange world of mathematical time-telling

What is modular arithmetic? In this video I'll introduce you to the strange world of mathematical time-telling that is modular arithmetic! What is the final digit of 7 to the power of 100? Can 4003 be written as the sum of two squares? Is 1,200,304,501 divisible by 3? All these are questions that are made much simpler by using modular arithmetic! In this video we'll go over the basics of what modular arithmetic is, and how to answer different questions when working in different modulos. I'll also explain the applications of modular arithmetic and why it's so important! Modular arithmetic is a fantastic tool for answering funky questions about numbers - and thus a great tool to add to your mathematics tool kit :) Here is the modular arithmetic hand-out which contains the formal definition of when two numbers are congruent to each other, as well as proofs of the addition and multiplication theorem: https://www.dropbox.com/s/3sn5p55sm0p3m5m/ModularArithmetic_MathsUnboxed_Handout.pdf?dl=0 Click here for a mini-series of videos on how to solve a variety of modular arithmetic questions: https://www.youtube.com/playlist?list=PLpw5dUNGvQBoG0t1Tnf_gYlWTn62XtuPW ------------ Subscribe to my youtube channel: https://youtube.com/mathsunboxed?sub_confirmation=1 Follow me on instagram: https://instagram.com/maths_unboxed Check out my Etsy store: https://www.etsy.com/uk/shop/CuriosityUnboxed