How does Santa deliver all of those presents?

We could try to work it out this way…

The Santa Claus Gift Momentum Equation

Santa Claus Gift Momentum Equation  

The Gift Probability Equation

Gift Probability Equation

Both equations have been reproduced here with permission. They originally appeared in this post The Mathematics Of Santa Claus’ Present Delivery System by William M Briggs

But Math is not just for Christmas! Are mathematical equations part of your daily life?

Math pops up in some form or other on a regular basis for all of us, so today we are focusing on calculator apps that can help you survive it! Three very different calculator apps are featured below starting with the more basic app PhotoMath, before moving into a handwriting calculator app MyScript Calculator, and then finally a graphing calculator called  Desmos. All three apps are available for free from iTunes and Google Play.

photo math app logo


Using the camera of your device, PhotoMath scans a typed (rather than handwritten) mathematical equation and provides you with the answer. It’s that simple! However, the most valuable function of the app is that it also provides you with a step-by-step account of how it arrived at the answer. That’s the cool bit I think in this app.

*This app will really help read/write learners who are struggling with the equation to access or take in the information so as to understand the answer when they can read the solution step by step. 

This is new enough app and they constantly improving it. If you happen to come across an equation that it can't solve, pass it on to the support team. 


Screenshot of Photo Math

screenshot of Photo math

A video about Photo Math

my script calculator logo

My Script Calculator

When using this app, you can write a mathematical equation on the screen using either your finger or a stylus, then MyScript Calculator converts your handwritten symbols and numbers into digital text before providing you with the answer to the sum or equation! You can copy your results to the clipboard or export them to other apps. For €0.99 you can unlock the ‘PowerPack’ from within the app which saves your calculations to memory and allows you to use them at any time in future calculations. Kinesthetic learners, who benefit from using all of their senses when accessing information, will like the fact that they can write the equation themselves. The act of writing it will help them process it whilst still being able to draw on the power of the calculator app to solve the equation for them.


Screenshot of MyScript Calculator

my script calculator screen shot

A Video about MyScript Calculator

desmos app logo


This graphing calculator is available to you via either the app or via your browser, and you can choose to use it in 33 different languages! Using Desmos, you can plot functions, create tables, add sliders, and animate your graphs, and all while offline too! You can also type in any equation you want to solve, and it’ll show you the answer. The visual and kinesthetic learners amongst you will love this app for accessing and engaging with mathematical concepts.


Desmos Screenshot

desmos screenshot

A video about Desmos

Desmos have also provided a series of help videos on YouTube. The videos are all short and to the point and do a great job of explaining quickly exactly what you’re looking for.

desmos screenshot

You can even try your hand at some creative function art too!

*Thanks goes to Damien Raftery, a lecturer at the Institute of Technology Carlow, Ireland, who contacted us and suggested Desmos for The 12 Apps of Christmas!

Optional Task

Optional Task
  1. Depending on your mathematical needs, choose one of the apps above and have a go!

  2. If anyone tries some creative functional art, we’ve love to see your efforts at #12appsDIT 
    (how about a Santa Claus?!)

Don’t forget to tweet comments, tips and hints about these calculator apps to #12appsDIT