Combination of "blunder" and "number crunching," describing the exasperating experience of trying to figure out which supermarket item is giving you more for your
money on a dollar per ounce basis.
A lot of times these days supermarkets
will break down the cost per ounce right on the face of the shelf price
tag. However, sometimes you find yourself blundering through basic
algebra, trying your best to hold your own. Forget about it if you're trying to convert between grams and ounces: you're just done, and you'll make your decision on some other factor.
If you have your
phone with you, you can use the calculator function to avoid blunder crunching. In no case, however, must you mumble to yourself out loud as you try to do the calculations.