I'm 14 and still call my mom mommy D:

my 14 year old foster brother constantly called his mother mommy.

You're bad at math. A quarter million dollar coins, if stacked, would be 1,600 feet high, and the whole thing would weigh 4,400 pounds. So if you know of a piggy bank that can hold over two tons, let me know.

Math has absolutely everything to do with it. The volume of a single Sacagawea dollar (the smallest dollar coin I'm aware of) is .067 cubic inches. Not much. But 250,000 of them has a volume of 16,777 cubic inches. That's only if stacked efficiently.
Assuming a 70% space use (to explain any air between the coins) that makes it 19,172 cubic inches. That calculates out to 1,597 cubic feet. Take the cube root and you get 11.66. You would need a cube 11.6 feet in all directions to hold that many coins.
I don't know who told you about that piggy bank, but it wasn't true.

Oh my goodness are you serious. Did you actually WATCH someone put 250,000 dollar coins into a piggy bank? No! I don't know who told you this could possibly happen, but they are wrong.
Or you're just a dumb troll who calls for his "mommy" every time the internet says he's wrong.

Another problem- counting at a rate of 5 coins per second (which is insanely fast) it would take 14 hours to count them all. At a rate of 1 per second, it would take 70 hours. To do it in 3 hours would be 23 coins per second. That's faster than most automatic weapons fire.

I've tried. I can't find it anywhere. I've searched for "world record coins piggy bank," "video coins bank,"267,000 dollars coins" and several other things. Please find it for me and send me the link.
And while I'm at that, you need to consider the possibility that this is 100% impossible under any conditions.

Seriously. You don't get it: that many coins would fill your bedroom up to your knees.

Oh shit.....
I will take a moment to fill your ego.
The video I saw was off of a satirical website that no longer exists. It parodies the proofs of world records which used to be videos that would skip out a lot of the long parts. Yesterday I looked for the video and couldn't find it, so I asked my father, who'd shown it to me first.

This was 8 years ago, I was only 8 at the time. Why do we still believe the ridiculous stuff our parents tell us when we're young?

Also, it was my mistake, I was wrong, and I look, feel like, and am an idiot for this. =)

Behold the power of math :P