Canvas is not supported in your browser.
Find the area of the square. Both the width and height are 23 units each.
Surface Game Graphic
Tap digits, then drop them in the white answer box.

Surface Game

Tap and drop digits to the middle white answer box. Answer math questions about each graphic, as it displays. Select the Final Answer button when you're ready.

The free game design tutorial teaches how to create this game. Learn to make your own game with the HTML5 Game Tutorial for Beginners.

Surface Game: Page 35