Earlier this evening I saw the following picture posted by Mathster (@mathstermaths)
As I tweeted I am really not keen on the use of “move all terms to the left” as I don’t think it is clear what this is meant to mean mathematically. Indeed, it could easily lead to misconceptions with people thinking that you just move terms over an equals sign with no conceptual understanding of what should be happening. Stephen Cavadino (@srcav) has written about this here.
I thought I would try going online and doing the same equation as is solved in the example. The step by step solution I obtained was even stranger:
Christine (@MissNorledge) also pointed out the strange behaviour this app shows when rounding. According to the example above 8/3 rounds to 2.666666666666665. To me this indicates poor use of floating poor arithmetic.
Jasmina then showed something that is clearly a bug in their parsing library
- How the user input is being parsed?
- How is the “maths” implemented?
The app can’t solve quadratics with complex roots or cubics: