Use reasoning to lead to the answer of the following question:
Yesterday, David and William were invited to a party. David broke 2 glasses, while his friend William broke 4 times the number of glasses David broke. How many glasses were broken?

10
William broke 4 * 2 = 8 glasses.

So, David and William broke 8 + 2 = 10 glasses.

.

Therefore, the answer is 10