Oct. 10th, 2017 12:13 am

### (no subject)

**gregh1983**

Here is how I passed the time walking home from the gym tonight:

I was thinking about mulch for the yard. So far, the only way we've been able to acquire it is by walking it home a bag or two at a time from Home Depot: I can carry one on my back, and Alan can push one in a little cart we have. If we lived in the suburbs, we could order a much larger quantity from a serious garden center and have it dumped in our driveway. Presumably, we could also show up at such a place with a car and as many containers as we could muster, and the mulch could be loaded into those just as well. This would let us pick from a selection of mulch types that don't come in bags, and the stuff is probably cheaper in bulk too. On the other hand, the scheme would only work if our various containers added up to significantly more than the two little bags we can already carry home unassisted.

The capacities of large, yardwork-sized containers seem to be given in gallons. A bag of mulch from Home Depot is 2 cubic feet. What's the equivalence between the two? What can I work out mentally, while walking, based on the facts I have on hand?

Well, one gallon is 3.8 liters, which is equivalent to a volume of 38 × 10 × 10 cm. Then two gallons would be 76 × 10 × 10, and three gallons is 114 × 10 × 10. Continuing, 30 gallons is 114 × 100 × 10, and 300 gallons is 114 × 100 × 100 cm. This is 1.14 cubic meters. Now 1.14 is annoyingly bigger than 1, so let's knock 10 percent off each side: 1.14 – 0.11 = 1.03 cubic meters = 300 – 30 = 270 gallons. We're still not quite at 1. Let's fudge the numbers and say that 3 percent of 100 is close enough to 3 percent of 103, and so we subtract (27... 54... 81) 270 – 8.1 = 262 gallons. All right, so 1 cubic meter equals 262 gallons. Now we have to go back into imperial units. A meter is something like 39 inches, which we can call 3⅓ feet for convenience. That would make a cubic meter equal to 10 × 3⅓ = about 33 cubic feet. While 33 × 9 is sounding too big, we do see that 33 × 8 = 240 + 24 = 264, which shows that the ratio beteen cubic feet and gallons is essentially 1 to 8. Therefore — whew! — one cubic foot is 8 gallons, and a standard bag of mulch is 16. Ha ha!

That laugh has a dual purpose. One of satisfied achievement, since I was able to work out what I wanted to know in the time it took me to get home roughly from Aldi's. (And, you know, when I spent three seconds just now to get the exactly correct answer out of Google, it turns out to be 7.48.) The other, though, is of caustic sarcasm, because 16 gallons is already our entire supply of five-gallon buckets — if I empty them all first. I could of course press into service our 30- or 35-gallon trash barrel, but it would have to be a pretty impressive type of mulch not available in bags to make it worthwhile. Otherwise, it'd be 2 × 8 – 7 + 1 = 10 times easier to just borrow a car and pick up a few bags from Home Depot!

I was thinking about mulch for the yard. So far, the only way we've been able to acquire it is by walking it home a bag or two at a time from Home Depot: I can carry one on my back, and Alan can push one in a little cart we have. If we lived in the suburbs, we could order a much larger quantity from a serious garden center and have it dumped in our driveway. Presumably, we could also show up at such a place with a car and as many containers as we could muster, and the mulch could be loaded into those just as well. This would let us pick from a selection of mulch types that don't come in bags, and the stuff is probably cheaper in bulk too. On the other hand, the scheme would only work if our various containers added up to significantly more than the two little bags we can already carry home unassisted.

The capacities of large, yardwork-sized containers seem to be given in gallons. A bag of mulch from Home Depot is 2 cubic feet. What's the equivalence between the two? What can I work out mentally, while walking, based on the facts I have on hand?

Well, one gallon is 3.8 liters, which is equivalent to a volume of 38 × 10 × 10 cm. Then two gallons would be 76 × 10 × 10, and three gallons is 114 × 10 × 10. Continuing, 30 gallons is 114 × 100 × 10, and 300 gallons is 114 × 100 × 100 cm. This is 1.14 cubic meters. Now 1.14 is annoyingly bigger than 1, so let's knock 10 percent off each side: 1.14 – 0.11 = 1.03 cubic meters = 300 – 30 = 270 gallons. We're still not quite at 1. Let's fudge the numbers and say that 3 percent of 100 is close enough to 3 percent of 103, and so we subtract (27... 54... 81) 270 – 8.1 = 262 gallons. All right, so 1 cubic meter equals 262 gallons. Now we have to go back into imperial units. A meter is something like 39 inches, which we can call 3⅓ feet for convenience. That would make a cubic meter equal to 10 × 3⅓ = about 33 cubic feet. While 33 × 9 is sounding too big, we do see that 33 × 8 = 240 + 24 = 264, which shows that the ratio beteen cubic feet and gallons is essentially 1 to 8. Therefore — whew! — one cubic foot is 8 gallons, and a standard bag of mulch is 16. Ha ha!

That laugh has a dual purpose. One of satisfied achievement, since I was able to work out what I wanted to know in the time it took me to get home roughly from Aldi's. (And, you know, when I spent three seconds just now to get the exactly correct answer out of Google, it turns out to be 7.48.) The other, though, is of caustic sarcasm, because 16 gallons is already our entire supply of five-gallon buckets — if I empty them all first. I could of course press into service our 30- or 35-gallon trash barrel, but it would have to be a pretty impressive type of mulch not available in bags to make it worthwhile. Otherwise, it'd be 2 × 8 – 7 + 1 = 10 times easier to just borrow a car and pick up a few bags from Home Depot!