9 Calculează, grupând convenabil termenii.
a. 276 + 359 + 124
b. 326 + 247 + 134 + 73
382 + 172 + 108
275 + 187 + 125 + 213
c. 8+
9 + 10 + 11 + 219 + 210 +231 +242
11 + 12 + 13 + 14 + 189 + 188 + 187 + 186
36 + 147 + 68 + 172 + 214 + 182 + 103 + 78​

Răspuns :

Răspuns:

a. 276+359+124

276+124=400

400+359=759

b. 326+247+134+73

326+134=460

247+73=320

460+320=780

382+172+108

382+108=490

490+172=662

275+187+125+213

275+125=400

187+213=400

400+400=800

8+9+10+11+219+210+231+242

8+242=250

9+231=240

10+210=220

11+219=230

250+240+220+230=940

11+12+13+14+189+188+187+186

11+185=200

12+188=200

13+187=200

14+186=200

200+200+200+200=800

36+147+68+172+214+182+103+78

36+214=250

147+103=250

68+182=250

172+78=250

250+250+250+250=1000

Răspuns:

a)276+359+124=

635+124=759

b)326+247+134+73=

537+134+73=

707+73=780

c)8+9+10+11+219+210+231+242=

17+10+230+441+242=

27+230+683=

257+683=940

d)11+12+13+14+189+188+187+186=

23+27+377+373=

50+750=800

e)36+147+68+172+214+182+103+78=

183+240+396+181=

423+577=1000