3. Oblicz.
54 + 37 =
43 + 29 =
27 + 18 =
87 - 59 =
74 - 37 =
92 - 19 =​


Odpowiedź :

[tex]54+37 = 50 + 4 + 30 + 7 = 80 + 11=91\\\\43 + 29 = 40 + 3 + 20 + 9 = 60 + 12 = 72\\\\27 + 18 = 20 + 7 + 10 + 8 = 30 + 15 = 45\\\\87-59 = 80 + 7 - 50 - 9 = 30 -2 = 28\\\\74 - 37 = 70 + 4 - 30 - 7 = 40 -3 = =37\\\\92 - 19 = 90 + 2 - 10 - 9 = 80 -7 = 73[/tex]

Odpowiedź:

54 + 37= 50 + 30 + 4+7= 80 + 11= 91

 43 +29= 40 +20 + 3 +9= 60 + 12=72

27+18= 20 + 10 +7 +8= 30 +15= 45

87- 59=  87 - 57 - 2= 30-2= 28

74- 37= 74- 34- 3= 40-3= 37

92-19=  92- 12 - 7= 80-7= 73

Szczegółowe wyjaśnienie: