37.2×5.4+3.28×54
=37.2×5.4+3.28×10×5.4
=37.2×5.4+32.8×5.4
=(37.2+32.8)×5.4
=70×5.4
=7×54
=378
0.8888×0.8+0.1111×1.6
=0.1111×8×0.8+0.1111×1.6
=0.1111×6.4+0.1111×1.6
=0.1111×(6.4+1.6)
=0.1111×8
=0.8888
9.99×7.78＋3.33×6.66
=9.99×7.78＋3.33×3×2.22
=9.99×7.78＋9.99×2.22
=9.99×(7.78＋2.22)
=9.99×10
=99.9