This isn't a homework question, fyi. I'm getting pissed about the answer I'm getting out of a equation because I know it's wrong, but I can't seem to figure it out. Here it is;

Let's just say you acquire and now have a 1000 grams of glyceryltrinitrate and it explodes, producing a 8.0x10^13 ergs of energy being fucking liberated. What is the mass of the products of the explosion?

Here's what I'm doing;

m= (E/(c^2))

m= (8.0x10^13) / (9x10^20) (= 8.888888889x10^(-8))

m= (9.9x10^2) = 999.9

But, here's the thing, I found a texted book on chemistry that actual has this same example and it gives the answer as (0.89x10^(-7)) giving the mass of products of the explosion as a whopping (999.999999911). Is the author rounding down from 8.888888889x10^(-8) to get 0.89x10^(-7)?

What am I doing wrong, bros?