a) ( 1267-196 ) - ( 267 + 304 )
= ( 1267 - 267 ) - ( 196 + 304 )
= 1000 - 400
= 600
b ) ( 3965 - 2378 ) - ( 437-1378 ) - 528
=
a, (1267-196)-(267+304)
=(1267-267)-(196+304)
=1000-500
=500
b; (3965-2378)-(437-1378)-528
=(3965-528-437)-(2378-1378)
=3000-1000
=2000