Question

Dau Coronița! Calculați rapid ca în exemplul de mai sus (din chenarul mov) ex8

Answer 1

5*99=5*(100-1)=5*100-5*1=500-5=495

99*8=8*(100-1)=8*100-8*1=800-8=792

23*99=23*(100-1)=23*100-23*1=2300-23=2277

99*345=345*(100-1)=345*100-345*1=34500-345=34155

103*99=103*(100-1)=103*100-103*1=10300-103=10197

999*25=25*(1000-1)=25*1000-25*1=25000-25=24975

999*63=63*(1000-1)=63*1000-63*1=63000-63=62937

222*999=222*(1000-1)=222000-222*1=221778