Puzzles - Number puzzles

226.
Answer
:
4
Explanation
:
Working in rows, starting with the central row, add the left and right hand digits together and put the result in the central space. Repeat for the upper and lower rows, but put the result in the opposite central space.

227.
Answer
:
25
Explanation
:
Starting on the left, halve the first number and add it to the second number to give the next one along. Repeat this sequence all the way to the right.

228.
Answer
:
6
Explanation
:
As you move down, numbers represent the reverse alphabetical values of the 5 vowels.