a, 5 3 + 3 4 + 4 . 2 + 27 - 3 : 4
= 125+170+6
= 301
b, 124 : 3 2 . 7 - 1 10 + 24 : 5 2
= 124:[9.7–(1+24):25]
= 124 : [63–25:25]
= 124:62
= 2
c, 245 - 4 16 : 8 + 2 4 . 3 2 - 9
= 245–4[2+2.27]
= 245–4.45
= 29
d, 375 : 5 3 - 3 8 : 3 6 - 2 . 2 3
= 375 : 125 – (9–16)
= 3–9+16
= 10