1. The problem states: 70% of what number is 10. 2. Let the unknown number be $x$. 3. "70% of $x$" means $70\% \times x$ or $0.7x$. 4. The equation representing the problem is: $$0.7x = 10$$ This equation states that 70% of $x$ equals 10. No further solving is required as per the instructions.