First represent the two given numbers by dragging the balls to the grey parts, then start the adding: 5 I's equal one V. So if you have 5 balls or more on the line of units

• drag 5 balls to the red part of the line
• drag 1 ball on the line of fives from the red part to the grey part.

Do the same for the tens and the hundreds. 2 V's equal one X. So if you have 2 balls or more on the line of fives

• drag 2 balls to the red part of the line
• drag 1 ball on the line of tens from the red part to the grey part.

Do the same for the fifties and the five hundreds. Continue until the sum of the two numbers is represented properly in Roman numerals. The reset button resets all balls to restart the same exercise. The new button generates a new random exercise.