（1.25+2.5）×16 ＝ 1.25×16 +2.5×16 =1.25×8×2+2.5×4 ×4=20+40=60
1.25×3.7×0.8＝1.25×0.8×3.7=1 ×3.7=3.7
3.4×9+3.4＝3.4×9+3.4×1=3.4×(9+1)=3.4×10=34
9.24×9+3.4＝ 9.24×(10-1)+3.4=92.4-9.24+3.4=95.8-9.24=86.56

愿对你有所帮助!