( 87.3 × 47.7 - 1.98 ) ÷(4.76×87.4+0.199)
=10 ( 87.3 x 4.77 - 0.198 ) ÷ ( 4.76 x 87.4 + 0.199 )
=10 [ 87.3 x ( 4.76 + 0.01 ) - 0.198 ] ÷ [ ( 87.3 + 0.1 ) x 4.76 + 0.199 ]
=10 ( 87.3 x 4.76 + 0.873 - 0.2 + 0.002 ) + ( 87.3 x 4.76 + 0.476 + 0.2 - 0.001 )
=10
注:0.873 - 0.2 + 0.002结果和 0.476 + 0.2 - 0.001一样