## Prealgebra (7th Edition)

$\sqrt {157}$ is between $\sqrt {144}=12$ and $\sqrt {169}=13$ Divide by one of the square roots, then average: $157\div12=13.08\overline3$ $(12+13.08\overline3)\div2=12.541\overline6$ Repeat: $157\div12.542=12.518$ $(12.542+12.518)\div2=12.53$