Solve equation: Mr. Shaw tithes one-tenth of his income. His last tithe check was $213. How much income did he tithe on?

1. Let \( x \) be the income Mr. Shaw tithed on.
2. Set up the equation for the tithe as one-tenth of the income:
\frac{1}{10} \cdot x = 213
3. Solve for \( x \) by multiplying both sides by 10:
x = 213 \times 10
4. Calculate the result:
x = 2130

Mr. Shaw tithed on an income of 2130 .