a) 24 +117 + 115 + 176 + 83
=(24+176)+(117+83)+115
= 200+200+115
=515
b) 17.57 + 43.17 + 29
=17.(57+43)+29
=17.100+29
=1700+29
=1729
c) 47.164 + 164.53 + 5 . 43
=164.(47+53)+5.64
=164.100+320
=16400+320
=16720
d)194.12 + 6.437.2 + 3.369.4
=194.12 + 437.12 + 369.12
=12.(194+437+369)
=12.1000
=12000