Hi Alexander! I'm so glad you liked it and I appreciate your feedback! I actually talk about why I didn't include the equivalent of an on-screen calculator in my blog post. At an earlier level of learning it would make sense to reinforce the idea that if you're spending something then you'll be left with less money in your pocket, but in this case the challenge is closer to what you'd face in real life: You have this much money - the yummy items you want cost this much - how much can you buy? At some point in your development you've got to either do the calculation in your head or figure it out some other way as you're standing there in the store - and that's what I was going for. And what better place to practice than in a no-risk, worry-free elearning environment? Nonetheless there are a ton of other learning elements I wanted to add if I ever get the time - and I mention those in my post too:
http://www.jackievannice.com/?p=175067017 Thanks so much for your comments, Alexander! I'm so glad you're becoming a challenge regular. :)