Răspuns :
Răspuns:
1) a) 1927+3008=4935
Proba: 4935-3008=1972
6175+2999=9175
Proba:9175-2999=6175
b) 6000-2873=3127
Proba:3127+2873=6000
8001-4564=3437
Proba: 3437+4564=8001
c) 10000-5709-2543=1748
Proba: 1748+2543+5709=10000
2017+1360+3808=7185
Proba: 7185-3808-1360=2017
2)diferenta: 4012-2756= 1256
suma: 889+2019=2908
"Adauga diferenta la suma deci"
2908+1256=4164
3)a)9011-6148=2863
b)1972+1029=3001
c)7000-4088=2912
d)1000+0=1000
Ordinea: 1000, 2863,2912,3001
4.a)2305+178+4211=178+6516=6694
b)5342+2739-1899=8081-1899=6182
c)10000-3600+3019=6400+9419=15819
5)a) (10+20+30)+(15+25)= 60+40=100
b) (50+100+150)+(75+125)=300+200=500
c) (2500+3500)+(782+218)=6000+1000=7000
d) (2400+3600)+(520+80)=6000+600=6600
6)A) (1450+2300)+3007=1450+(2300+3007)
3750+3007=1450+5307
6757=6757 (adevărat)
B) 6800-2100-1820=6800-(2100+3007)
4700-1820=6800-5107
2880=1707 (fals)
7)1.cati pruni sunt?3000-1005-785=1210
al doilea mod:
1.cati meri si peri sunt in total?1005+785=1790
2.cati pruni sunt?3000-1790=1210
Explicație pas cu pas: