Question

84乘以28再加22简便计算

Answer 1

84x28+22
=84x（30-2）+22
=84x30-84x2+22
=2520-168+22
=2520-146
=2374
84x28+22
=84x（20+8）+22
=84x20+84x8+22
=1680+672+22
=1680+694
=1680+700-6
=2380-6
=2374

Answer 2

100×7.9+184×2.1+84×2.9 =100×7.9+100×2.1+84×2.1+84×2.9 =100×（7.9+2.1）+84×（2.1+2.9） =100×10+84×5 =1000+420 =1420