Calculează după model: 276+7=283 =200+70+6+4+3 =200+70+10+3 =200+80+3 =283 763+29=700+60+3+20+9 =700+60+3+20+7+2 =700+80+10+2 =700+90+2 =792 345+647=300+40+5+600+40+7 367+529= =300+40+5+600+40+5+2 -992 =900+80+10+2 =900+9b+2 654+38= 11 45 + 568+ 604+​