[tex]\dfrac{5}{7}\ of\ 100:\\\\\dfrac{5}{7}\cdot100=\dfrac{5\cdot100}{7}=\dfrac{500}{7}=\dfrac{70+28+2}{7}=\dfrac{70}{7}+\dfrac{28}{7}+\dfrac{2}{7}\\\\=10+4+\dfrac{2}{7}=14\dfrac{2}{7}\\\\\dfrac{2}{7}\ \text{is smaller than}\ \dfrac{1}{2}.\ \text{Therefore}\ 14\dfrac{2}{7}\approx14\\\\Answer:\ \boxed{14}[/tex]