In a two-digit number the units digit is twice the tens digit. On reversing the digits, the new number is 36 more than the original. Find the original number.

Three steps:
1. **Pick a variable** for the unknown.
2. **Translate the words** into operations (sum, difference, product, quotient).
3. **Solve, then state the answer in the original units.**

Word clues: 'is/equals' = '='. 'sum' = +. 'difference' = −. 'product' = ×. 'quotient/per' = ÷. 'twice' = ×2. 'one more than' = +1. 'half of' = $\times \frac{1}{2}$.