Number patterns and missing numbers
Work out the jump from one term to the next, then keep applying that same jump.
A worked example
In 40, 46, 52, 58 each term is 6 more than the one before, so the next term is 58 + 6 = 64.
The mistake people actually make
A pattern is only an add-the-same-amount pattern if the gap is identical every time, so check every pair of terms, not just the first two.