Matematyka wokół nas klasa 4 ćwiczenia częśc zadanie 5 . str.39 Oblicz i skróć jesli mozna : a) 4 x 3 1/2 3 x 5 1/3 5 x 4 1/5 b) 2 x 1 2/3 2 x 1 2/8 2 x 2 3/4 c) 3 x 1 1/3 3 x 2 2/3 3 x 2 1/6 d) 4 x 2 1/4 4 x 2 3/4 4 x 1 1/7

a)   4  * 3  i 1/2=   = 4 * 7/2= (skracam 4 z2)   = 2* 7/1=   = 14/1=   = 14       3 * 5 i 1/3=   = 3 * 16/3 = ( skracam 3 z 3)   = 1 * 16/1=   = 16/1=   = 16         5 * 4 i 1/5=   = 5 * 21/5=  ( skracam 5 z 5)   = 1 * 21/1=   = 21/1=   = 21       b)   2 * 1 i 2/3=   = 2 * 5/3=   = 10/3=   = 3 i 1/3       2 * 1 i 2/8=   = 2 * 10/8 = (skracam 2 z 8)   = 1 * 10/4=   = 10/4=   = 2 i 2/4=   = 2 i 1/2         2 *  2 i 3/4=   = 2 * 11/4= (skracam 2 z 4)   = 1 * 11/2=   = 11/2=   = 5 i 1/2       c)   3 * 1 i 1/3=   = 3 * 4/3= (skracam 3 z 3)   = 1 * 4/1=   = 4/1=   = 4         3 * 2 i 2/3=   = 3 * 8/3 = (skracam 3 z 3)   = 1 * 8/1=   = 8/1=   = 8       3 * 2 i1/6=   = 3 * 13/6 = (skracam 3 z 3)   = 1 * 13/2=   = 13/2=   = 6 i 1/2          d)   4 * 2  i 1/4=   = 4 * 9/4= 9skracam 4 z 4)   = 1 * 9/1 =   = 9/1=   = 9         4 * 2 I 3/4=   = 4 * 11/2=  (skracam 4 z 2)   = 2 * 11/1=   = 22/1=   = 22       4 * 1 i 1/7=   = 4 * 8/7=    = 32/7=   = 4 i 4/7

4x3 1/2=4/1x7/2=28/2=14 3x5 1/3=3/1x16/3=48/3=16 5x4 1/5=5/1x21/4=105/4=26 1/4 2x1 2/3=2/1x8/3=16/3=5 1/3 2x1 2/8=2/1x18/8=36/8=4 2x2 3/4=2/1x11/4=22/4=5 2/4 =5 1/2 3x1 1/3=3/1x4/3=12/3=4 3x2 2/3=3/1x8/3=24/3=8 3x2 1/6=3/1x13/6=39/6=6 3/6=6 1/3 4x2 1/4=4/1x9/4=36/4=9 4x2 3/4=4/1x11/4=44/4=11 4x1 1/7=4/1x8/7=32/7=4 4/7