0.654+10.9*6.5怎樣簡算

0.654+10.9*6.5怎樣簡算

=0.1*(6.5+0.04)+10.9*6.5
=(10.9+0.1)*6.5+0.004
=(10+1)*6.5+0.004
=65+6.5+0.004
=71.504