23. How many matches can be obtained from a wooden cube with an edge of 1 m, if each match must have a length of 5 cm, a width of 2 mm, and a height of 2 mm? (Assume that no material is lost to sawing.)
23. $1 \mathrm{m}^{3}=1000000 \mathrm{~cm}^{3}$; one match has a volume of $5 \cdot 0.2 \cdot 0.2=0.2\left(\mathrm{~cm}^{3}\right)$; $1000000: 0.2=5000000$. Therefore, 5 million matches.