An exercise machine with an original price of $\$ 670$ is on sale at $10 \%$ off. a. What is the discount amount? b. What is the exercise machine's sale price? a. discount amount $=\$ \square$

Step 1 ：The original price of the exercise machine is $670.

Step 2 ：The discount rate is 10%, or 0.10 in decimal form.

Step 3 ：To calculate the discount amount, we multiply the original price by the discount rate. So, the discount amount is \(670 \times 0.10 = 67\).

Step 4 ：\(\boxed{67}\) is the discount amount.

Step 5 ：To find the sale price, we subtract the discount amount from the original price. So, the sale price is \(670 - 67 = 603\).

Step 6 ：\(\boxed{603}\) is the sale price of the exercise machine.