2,75 + 0,08(3) - 1,(2) =
= 275/100 + (83-8)/900 - (12-1)/9 =
= 275/100 + 75/900 - 11/9 =
= 9×275/900 + 75/900 - 11×100/900 =
= 2475/900 + 75/900 + 1100/900 =
= 3650/900 =
= 4,0(5)
- 0,69(4) + 1,(6) - 1,875 =
= - (694- 69)/900 + (16-1)/9 - 1875/1000 =
= - 625/900 + 15/9 - 1875/1000 =
= -( 625×10)/9000 + 15×1000/9000 - 9×1875/9000 =
= - 6250/9000 + 15000/9000 - 16875/9000 =
= 8750/9000 - 16875/9000 =
= - 8125/9000 =
= - 0,902(7)