(1)16.75-(6.75+3.15),=16.75-6.75-3.15,=10-3.15,=6.85;(2)( 2 9 + 6 7 × 7 18 )÷ 7 6 ,=( 2 9 + 1 3 )÷ 7 6 ,= 5 9 × 6 7 ,= 10 21 ;(3)25×1.25×32,=(25×4)×(1.25×8),=100×10,=1000;(4)(3.75+4.1+2.35)×9.8,=10.2×9.8,=99.96.