Sales for the month were $650,000, 85% of sales were on account. Gross margin is 40% of sales.

To calculate the amount of sales made on account, you can multiply the total sales by the percentage of sales made on account.

Sales on account = Total sales * Percentage of sales on account

Sales on account = $650,000 * 0.85 = $552,500

To calculate the gross margin, you can multiply the total sales by the gross margin percentage.

Gross margin = Total sales * Gross margin percentage

Gross margin = $650,000 * 0.40 = $260,000