Darien ordered soda for $2.75, a sandwich for $8.50, and a dessert for $3.85. Sales tax was $1.15. Use mental math to find the total amount of the bill. Explain

What I would do is start with the price of the dessert and the sales tax $3.85 + $1.15 = $5. I started with this because when you add the cents they equal a dollar which makes it easier to continue.

Then I would add the 2.75. This would be 7.75.

Then add 7.75 + 8.50. To simplify this, you can add 7 + 8, then. 75 +.50

Which would equal 15 + 1.25 + 16.25