Oy, always with the Wolfram Alpha! Yeah, it’s a neat toy. Anyway, let’s see what cool/interesting/useful stuff we can do with it.
So this trick is kind of mathy but I’ll explain as I go and we’ll let Wolfram Alpha do all of the heavy lifting.
Let’s assume I’m trying to put together a diet plan. I like bananas and greek-style yogurt so I want to have a diet consisting of just those foods. However, I’m not dumb so I’ll want to make sure I get enough nutrients from my diet plan so I don’t, you know, die of malnutrition or some such junk.
So what nutrients am I worried about? I’m mainly concerned about getting enough calcium and iron. (For the rest I’ll just take supplements or something.)
But how much should I get each day of each? Let’s ask Wolfram Alpha:
rdi calcium;rdi iron
NOTE: you can combine queries by using a semi-colon. Very handy. Also, RDI is Recommended Daily Intake.
So how what’s in a banana?
All right, how many micrograms is a milligram, Wolfram Alpha?
micrograms in a milligram?
(Quiet, you. I used to know this.) Looks like there are 1000 micrograms in a milligram so a banana has .307 mg of iron. (I want everything in milligrams to make the math easier.)
How about greek-style yogurt? The individual servings are five ounces, so:
five ounces plain greek yogurt
So I need 1000 milligrams of calcium and 18 milligrams of iron per day. How much yogurt and bananas do I have to eat to get my recommended allowance? Fortunately, Wolfram Alpha will tell me (once I frame the question properly, of course).
If I get 188 mg of calcium from five ounces of greek yogurt and 5.9 mg from a banana and I need 1000 mg per day, the equation is:
188X + 5.9Y = 1000
where X is the number of five ounce containers of yogurt and Y is the number of bananas. Let’s do something similar for iron:
.225X + .307Y = 18
Now there are all sorts of values you can plug into each individual equation but I want the values that work for both equations. So let’s ask:
188X + 5.9Y = 1000;.225X + .307Y = 18
I will need to eat about three and one-half containers of plain greek-style yogurt and fifty-six bananas per day to meet my requirements for calcium and iron. (In case, I’m dubious about this solution, Wolfram Alpha even offers to take me through the steps it used.)
So it looks like this nutrition thing is more complicated than I thought.