Question

calculeaza dupa modelul dat :

model:2x312=2x(300+10+2)
=2x300+2x10+2x2
=600+20+4
=624
a) 123x3
241x2

b) 5x111
2x243

Answer 1

a) 123 * 3 = 3 (100 + 20 + 3) =
3 * 100 + 3 * 20 + 3 * 3 =
300 + 60 + 9 =
369
241 * 2 = 2 * (200 + 40 + 1) = 
2 * 200 + 2 * 40 + 2 * 1 =
400 + 80 + 2 = 
482
b) 5 * 111 = 5 * (100 + 10 + 1) =
5 * 100 + 5 * 10 + 5 * 1 =
500 + 50 + 5 =
555
2 * 243 = 2 * (200 + 40 + 3) =
2 * 200 + 2 * 40 + 2 * 3 =
400 + 80 + 6 =
486 

Answer 2

a)
123x3=3(100+20+3)
=3x100+3x20+3x3
=300+60+9
=369

241x2=2(200+40+1)
=2x200+2x40+2x1
=400+80+2
=482

b)5x111=5(100+10+1)
=5x100+5x10+5x1=
500+50+5=
=555

2x243=2(200+40+3)=
=2x200+2x40+2x3=
=400+80+6=
=486