Question

Calculați după modelul prezentat

și cele care nu se văd :
15×202
5×1004​

Answer 1

Răspuns:

a)35×(100-1)=35×100-35×1=3500-35=3465

b)27×(100+1)=27×100+27×1=2700+27=2727

c)15×(100+2)=15×100+15×2=1500+30=1530

d)31×(100-2)=31×100-31×2=3100-62=3038

e)4×(1000-1)=4×1000-4×1=4000-4=3996

f)5×(1000+4)=5×1000+5×4=5000+20=5020

Answer 2

35•99=35•(100-1)=35•100-35•1=3500-35=3465

27•101=27•(100+1)=27•100+27•1=2700+27=2727

15×202=15•(200+2)=15•200+15•2=3000+30=3030

31•98=31•(100-2)=31•100-31•2=3100-62=3038

4•999=4•(1000-1)=4•1000-4•1=4000-4=3996

5•1004=5•(1000+4)=5•1000+5•4=5000+20=5020

Succes!