1. The problem states: "5 times a number D". We need to express this phrase as a mathematical expression. 2. The phrase "times a number" means multiplication. So, "5 times a number D" translates to multiplying 5 by D. 3. The mathematical expression is: $$5 \times D = 5D$$ 4. This means if you have a number D, multiplying it by 5 gives you the product 5D. Final answer: $$5D$$