黄冈小状元数学5年级上第七页培优作业

（1）2.9x0.45+0.29x4.2+0.029x13
=2.9x0.45+2.9x0.42+2.9x0.13
=2.9x(0.45+0.42+0.13)
=2.9x1
=2.9

（2）3.84x9.6+0.96x61.6
=3.84x9.6+9.6x6.16
=(3.84+6.16)x9.6
=10x9.6
=96