840÷56×64÷842×112÷16
=840×﹙1/56﹚×64×﹙1/842﹚×112×﹙1/16﹚
=[840×﹙1/842﹚]×[﹙1/56﹚×112]×[64×﹙1/16﹚]
=840×﹙1/842﹚×2×4
=840x8x1/842
=840x4x1/421
=3360/421
此题是不是应该把842 换成840?