# The New Math

• Erm... last time I checked 1oz is indeed 28g (give or take half a gram, which you'd only worry about if you were buying something stronger than pizza cheese)

• His point is that the serving size/number of servings and the total weight don't add up.

• I'm not seeing the WTF here either.

1 oz = 28g
81 oz = 81 * 28g
5 lbs = 2.27 kg

• 28g * 81 servings = 2.268kg which is pretty close to 2.27kg

As all the nutritional information is calculated in metric I would expect this to include the serving size - even though for US consumers the pack size and serving size are made to be (within reasonable rounding) simple values in US customary units.

• @Astaedus said:

I'm not seeing the WTF here either.

1 oz = 28g
81 oz = 81 * 28g
5 lbs = 2.27 kg

Yes, but 5 lbs != 81 oz

• 81 oz = 5.0625 lbs. Would you write out all the decimals?

• [quote user="Carnildo"][quote user="Astaedus"]

I'm not seeing the WTF here either.

1 oz = 28g
81 oz = 81 * 28g
5 lbs = 2.27 kg

[/quote]

Yes, but 5 lbs != 81 oz[/quote]

Ever heard of a concept called rounding? No? WTF!?

• [quote user="danielpitts"]

Ever heard of a concept called rounding? No? WTF!?

[/quote]

Sorry, but I'm with Daniel on this one.  Posting a WTF about bad math is one thing, but when it's your own bad math, that's really a WTF.

If you're going to post to a website that makes fun of stupid mistakes, you better be sure not to make them yourself.

• The title of this thread is "The New Math" and shows off an example of new math. Shockingly, this new math is the same as the old math!

The WTF here is that basic math isn't progressing! It's a stalled technology! If it doesn't keep up with the times it will surely become antiquated!

• Agreed. The real WTF is this:

1 lb = 16 oz.

5 lb = 80 oz.

1 serving = 1 oz

There are exactly 80 1-oz servings in a 5-lb bag, not 81.

• So there is a little rounding, somewhat humorous but not a massive wtf

• It's just simple rounding, as others have said.  A lesson in food labeling:

28 grams = 0.987670935 ounces (notice how the "28 grams" number is the significant number, NOT the "1 oz" number.)
0.987670935 ounces x 81 servings = 80.0013457 ounces
80.0013457 ounces = 5.00008411 pounds

Special note: when the labels say things like "0 grams of fat", it could really mean "0.44 grams of fat" and they are allowed to round down.  Same deal with zero calorie stuff.  At least, that's how I understand it.

• surely the WTF is putting 5 (or 5.06 or 5.000001) lbs of mozzarella on your pizza.

• WTF!? "Contains milk"!?

• Let's "invent" more WTF's for this...

"  ...  added to prevent caking."

WTF?  If they left it out it would turn into cake?  What kind, chocolate?  I'm partial to Angel Food, myself.

• "28 grams = 0.987670935 ounces"

Please consider the number of significant digits.

28 grams == 0.99 ounces (approximate)
-OR-
28.0000000 grams == 0.987670935 (precise)

Given that the numbers given are for food serving sizes and not delicate chemical formulas, I'm going to rule that the approximate numbers are Close Enough.

Is it a minor WTF to convert from Imperial to Metric and back to Imperial, introducing a small amount of error along the way?  Probably, but that's just how food labelling is done I guess.

• [quote user="Pap"]
(notice how the "28 grams" number is the significant number, NOT the "1 oz" number.)
[/quote]

I think that's part of the WTF.  Generally speaking, when you see <imperial measurement> (<metric equivalent>), that implies that the metric equivalent  is a rounded estimate, calculated from the imperial measurement.  e.g., "I weigh 202 pounds (92 kg)".  In this case, would you assume that I actually weigh 202 pounds (which is closer to 91.625 kg, in reality), or that I actually weigh 92 kg (which is actually closer to 202.825 pounds)?

This is further compounded by the fact that the bag is listed as weighing 5 lbs (2.27 kg).  So, do they actually fill the bags to 5 lbs in the factory (2.2679 kg) or do they fill it to 2.27 kg (5.00449 pounds)?  My money's on 5 pounds, exactly -- it's the only whole number, and this is in a country that uses imperial measurements.  Were we in a metric country, they'd probably sell 2 kilo bags as an equivalent offering; another nice, round number.

I think it's pretty safe to bet, taking all this into consideration, that the bag is measured in imperial units at the factory.  Similarly, american serving sizes are also measured in imperial units.

As such, selecting 28 grams as the significant number is just wrong, as it's almost certainly an approximation based on the 1 oz number.

So, the math should be simple.  The bag is 5 pounds at 16 servings per pound, which comes out to 80 servings.<font size="+1"></font>

The WTF is that the labeler selected an approximation as his significant number.

• I once bought a pie or cake or something that said:

Serving Size: 1/5

Now it seems to me that if the service size is 1/5, the number of servings per container would be exactly 5!

I wanted to call their product support line and complain that I cut the pie into fifths, but there were only 4 of them!

• The real WTF is that you buy that stuff instead of real mozzarella.

• [quote user="ahf"]The real WTF is that you buy that stuff instead of real mozzarella.
[/quote]

What would you suggest I use for making pizza, then?  The cheese is just there to glue the rest of the toppings on.

• Hmm... what is this miracle product? Is it like a 'cheese doily' that you just lay over your pizza? I have never seen such a thing, but that sounds pretty convenient. Although I prefer to shred the cheese myself.

• The real wtf is that someone pays that much attention to the number of servings in their 5lb bag of cheese.

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