A cube has 12 edges:
First cube has 10 cm edge, while the smaller cube has 8 cm edge. Subtract the measure of total length of their edges:
(12 × 10 cm) - (12 × 8 cm) = difference of total length their edges
120 cm - 96 cm = 24 cm
Final Answer: The total length of edges of bigger cube (with 10 cm edge) is longer by 24 cm than the smaller cube.