二、计算下面各题。
$15×27 - 3000÷25$ $(440 - 896÷32)×7$
$450÷(29 - 828÷36)$ $16×[882÷(105 - 84)]$
$(520 + 480)÷50×4$ $780 + 21×16 - 360$
$400 - (130÷65 + 35)$ $[868÷(98 - 91)]÷31$
$(736÷23 + 27)×15$ $480÷[(16 + 32)×2]$

15×27 - 3000÷25
=405 - 120
=285
(440 - 896÷32)×7
=(440 - 28)×7
=412×7
=2884
450÷(29 - 828÷36)
=450÷(29 - 23)
=450÷6
=75
16×[882÷(105 - 84)]
=16×[882÷21]
=16×42
=672
(520 + 480)÷50×4
=1000÷50×4
=20×4
=80
780 + 21×16 - 360
=780 + 336 - 360
=1116 - 360
=756
400 - (130÷65 + 35)
=400 - (2 + 35)
=400 - 37
=363
[868÷(98 - 91)]÷31
=[868÷7]÷31
=124÷31
=4
(736÷23 + 27)×15
=(32 + 27)×15
=59×15
=885
480÷[(16 + 32)×2]
=480÷[48×2]
=480÷96
=5