👤

Calculează după model:
42 x 40 = 58 x 30 =
52 x 80 =
67 x 50 =
42 x 400 =
58 X 300 =
52 x 800 =
67 x 500 =
32 x 20 = 32 x (2 x 10) =
= (32 x 2) X 10 =
= 64 x 10 = 640​


Răspuns :

a)42×40=42×(2×20)=(42×2)×20=84×20=1680.

b)52×80=52×(2×40)=(52×2)×40=104×40=4160.

c)67×50=67×(2×25)=(67×2)×25=134×25=3350.

d)42×400=42×(2×200)=(42×2)×200=84×200=16800.

e)58×300=58×(2×150)=(58×2)×150=116×150=17400.

f)52×800=52×(2×400)=(52×2)×400=104×400=41600.

g)67×500=67×(2×250)=(67×2)×250=134×250=33500.

h)58×30=58×(2×15)=(58×2)×15=116×15=1740.