Question

Model Marta has 15 dinner plates. She uses 9 of them for a party. How many of Marta's plates are not used? Explain your solution.​

Answer 1

6 plates are not used. The sum of the 9 plates used for the party and the 6 plates not used equals 15. Thus, subtracting 9 from 15 allowed us to determine that 6 plates were not used.

Explanation:

We know that of Marta's 15 dinner plates:

• 9 are used for a party,
• and the remaining number of plates are not used.

We can determine how many plates are not used by subtract 9 from 15:

Plates not sued = 15 - 9

Plates not used = 6

Thus, 6 plates are not used.