Answer:
n = 4
Step-by-step explanation:
Actually, in this problem, you can compare the numbers on the right to the numbers on the left and see that n must be 4 to make the lists match. (It's a problem in pattern matching.)
If you need to, you can rearrange the numbers:
(7 + 1) + n = (7 + 1) + 4
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If that doesn't work for you, you can add up the numbers on each side and form the equation ...
8 + n = 12
In second-grade terms, this is ...
8 + ___ = 12
Hopefully, you are sufficiently familiar with your math facts to know that 4 will complete this math fact.
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If that doesn't work for you, then invoke the addition property of equality and add -8 to both sides of the equation.
8 -8 +n = 12 -8
n = 4
