1) In this question, we can solve it in two different ways. Either algebraically, or by mental Math.
2) Algebraically we have:
[tex]\begin{gathered} a+4=10 \\ a+4-4=10-4 \\ a=6 \end{gathered}[/tex]By mental math, we just need to ask ourselves how much can I add to 4 and get 10,? The answer will be six.
3) Thus, the answer is 6
