3.21×8.2 87×0.18 0.82×54.9
=3.21×8.2 8.7×(10-8.2) 8.2×5.49
=(5.49 3.21)×8.2 8.7×10-8.7×8.2
=8.7×8.2 8.7×10-8.7×8.2
=87
321.321÷321×3.21
=321.321÷(321÷3.21)
=321.321÷100
=3.21321
3123 21 321 21 321 321 321 31 3
3.21×8.2 87×0.18 0.82×54.9
=3.21×8.2 8.7×(10-8.2) 8.2×5.49
=(5.49 3.21)×8.2 8.7×10-8.7×8.2
=8.7×8.2 8.7×10-8.7×8.2
=87
321.321÷321×3.21
=321.321÷(321÷3.21)
=321.321÷100
=3.21321