3.17+7.48-2.78+0.53-3.48-1.02+5.3
2个回答

3.17+7.48-2.78+0.53-3.48-1.02+5.3

=(3.17+0.53)+(7.48-3.48)-(2.78+1.02)+5.3

=3.7+4-3.8+5.3

=(3.7+5.3)+(4-3.8)

=9+0.2

=9.2