Johnny made an apple pie. he used 2/5 of a tablespoon of cinnamon and 3/10 of a tablespoon of nutmeg. how much more cinnamon than nutmeg did johnny use?

For this case, the first thing we should do is subtract the following expressions:
 2/5 of a tablespoon of cinnamon.
 3/10 of a tablespoon of nutmeg.
 Subtracting we have:
 (2/5) - (3/10)
 We apply the cross product:
 ((2 * 10) - (3 * 5)) / (5 * 10)
 Rewriting:
 ((20) - (15)) / (50)
 (5) / (50)
 1/10
 
 Johnny did use 1/10 more cinnamon than nutmeg

With a continuous thought process.