If David wants to purchase a home for $\$ 423,498$ and needs to pay $10 \%$ down, what will his down payment be? Do not type a dollar sign in your answer. Type your answer...

Step 1 ：To find out the down payment, we need to calculate 10% of the total cost of the home. This can be done by multiplying the total cost by 0.10.

Step 2 ：Let the total cost of the home be \$423,498, represented as \( total\_cost = 423498 \)

Step 3 ：Let the down payment percentage be 10%, represented as \( down\_payment\_percentage = 0.1 \)

Step 4 ：Calculate the down payment by multiplying the total cost by the down payment percentage, represented as \( down\_payment = total\_cost \times down\_payment\_percentage \)

Step 5 ：Substitute the given values into the equation to get \( down\_payment = 423498 \times 0.1 = 42349.8 \)

Step 6 ：Final Answer: The down payment will be \(\boxed{42349.8}\)