Question

11 Grupează convenabil termenii şi efectuează:
a) 11 + 12 +13 + 14 + 15 + 16 + 17 + 18 + 19
b) 63 + 78 + 25 + 17 +65 + 32=280
c) 270 +235 +372 +518 + 430 + 465 =
d) 2439 +95 + 0 + 1 + 4105 =
Verifică rezultatele obținute cu ajutorul calculatorului​

Answer 1

Răspuns:

●a)11+12+13+14+15+16+17+18+19=(11+19)+(12+18)+(13+17)+(14+16)+15 = 30+30+30+30+15=60+15=90+30+30+15=120+15=135

●b)63+78+25+17+65+32=280 A

●c)270+235+372+518+430+465=(270+430)+(235+465)+(372+518)=700+700+890=1400+890=2290

●d)2439+95+0+1+4105=(2439+1)+(95+4105)+0=2440+4200+0=6640+0=6640

Answer 2

Răspuns:

a) (11+19)+(12+18)+(13+17)+(14+16)+15= 30+30+30+30+15=120+15=135

b) (63+17)+(78+32)+(25+65)=80+110+90= 280

c(270+430)+(235+465)+(372+518)=700+700+890=2290

d)(2439+1)+(4105+95)+0=2440+4200=6640