Answer :

RhysH
604+406.64=1010.64
604-406.64=197.36
1010.64-197.36=813.28

813.28 is the difference
eah
[tex]604+406,64=1010,64 \ \ \ \ \ \ \ \rightarrow their \ sum \\ 604-406,64=197,36 \ \ \ \ \ \ \ \ \ \rightarrow their \ difference \\ 1010,64-197.36=\boxed{813,28} \ \ \ \ \ \ \ \ \leftarrow ANSWER[/tex]