Answer=5/8
An estimation of 5/8*9/10 would be about 5/8...
heres why....
when we estimate, we round numbers with up or down until we reach a problem that we can basically solve in our head. if you round 9/10 up to 1 then the problem becomes:
5/8*1
since we know that any number times 1 is itself we know that
5/8*1=5/8