a) 12 : { 400 : [500 – (125 + 25 . 7)]}
=12 : { 400 : [500 – (125 + 175)]}
=12 : [ 400 : [500 – 300)]
=12 : (400:200)
=12:2=6
b) 5 . 22 – 18 : 3
=5.4-6
=20-6=14
c) 18 : 3 + 182 + 3.(51 : 17)
=5+182+3.3
=187+9=196
d) 25 . 8 – 12.5 + 170 : 17 – 8
=200-60+10-8
=142
e) 2.52+ 3: 710 – 54: 33
=2.25+3:1-54:27
=50+3-2
=51
f) 189 + 73 + 211 + 127
=(189+211)+(73+127)
=400+200=600
g) 375 : {32 – [ 4 + (5. 32– 42)]} – 14 )
=375 : {32 – [ 4 + (160– 42)]} – 14 )
=375 : [32 – ( 4 + 118) – 14 ]
=375:(32-122-14)
=375:-104
=-375/104
h) (52022 + 52021) : 52021
=(52022:52021)+(52021:52021)
=5+1=6