Question

Как решить удобным способом?
25х38х4
5х17х4
25х36
35x18
8х45х25
240х25

Answer 1

25х38х4 = (25•4) • 38 = 100 • 38 • 3800

5х17х4 = (5•4) • 17 = 20 • 17 = 340

25х36 = 5•5 • 6•6 =
= (5•6) • (5•6) + 30•30 = 900

35x18 = 5•7 + 3•6 = (5•6) • (7•3) =
= 30 • 21 = 630

8х45х25 = 4•2• 45 • 25 =
= (4•25) • (2•45) = 100 • 90 = 9000

240х25 = 40 • 6 • 25 = (40•25) • 6 =
= 1000 • 6 = 6000

Answer 2

1) 25*38*4= 25*4*38=100*38=3800

2) 5*17*4= 5*4*17=20*17=340

3)25*36=25*4*9=100*9=900

4) 35*18=5*7*2*9=5*2*7*9=10*63=630

5) 8*45*25=25*4*45*2=100*90=9000

6) 240*25=25*4*60=100*60=6000