play.golang.org math error?

<p>This should be printing 50000, but instead prints 7050: <a href="https://play.golang.org/p/7GmMA0fI-C" rel="nofollow">https://play.golang.org/p/7GmMA0fI-C</a></p> <p>Just to verify, same code but in JavaScript: <a href="https://jsfiddle.net/2brhxd0r/" rel="nofollow">https://jsfiddle.net/2brhxd0r/</a></p>