1. **State the problem:** Find the difference of squares from 2 to 20. 2. **Recall the difference of squares formula:** $$a^2 - b^2 = (a-b)(a+b)$$ 3. **Apply the formula to the numbers 2 and 20:** $$20^2 - 2^2 = (20-2)(20+2)$$ 4. **Calculate the differences and sums:** $$= 18 \times 22$$ 5. **Multiply the results:** $$= 396$$ 6. **Final answer:** The difference of squares from 2 to 20 is $$396$$.