Okay, so we start at '$82'
$82
let's add $100
$82+$100=$182
lets add another 100
$82+$100+$100=$282
lets add another $100
$82+$100+$100+$100=382
lets add another $100
$82+$100+$100+$100+$100=$482
Now we can't add another $100, since that will take us to $582, and we need to get to $512, so lets add $20....
$82+$100+$100+$100+$100+$20=$502
Okay, we're getting really close! Let's add $10.
$82+$100+$100+$100+$100+$20+$10=$512
(If you were to show your work on a number line, you would simply keep moving up by $100 until you couldn't anymore, and then move up by $20, and finally by $10, until we get to $512)
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a simpler way to solve this...
Okay, so we start at '$82'
$82
let's add $400
$82+$400=$482
now lets add $30
$82+$400+$30=$512
**Hope this helps....