Question

Pythagoras was born about 582 BC. Isaac Newton was born in 1643

AD. How many years apart were they born.?

Answer 1

2,225 years apart.
You have to add the two numbers because BC or BCE is 582 years before the common era. 1643 is 1643 AD.
If you were to draw a number line, it would be like so...
|-------582-------------|-------------------1643-------|
^BC or BCE^ ^AD^
The space between them add up to 2,225 years apart.
Sorry if I wasn't clear. Hope it was helpful though.