To simplify the expression $43 + 5 + 7$, you can add the numbers together:

$43 + 5 = 48$

Then add 7 to the result:

$48 + 7 = 55$

So, the simplified value of the expression is:

$43 + 5 + 7 = 55$

Would you like further details, or do you have any other questions?

Here are 5 related questions to expand on this concept:

1. What is the associative property of addition?
2. How does the order of addition affect the result?
3. How can you use mental math strategies to simplify addition problems?
4. What is the commutative property of addition?
5. How do you handle addition problems with larger numbers?

Tip: When adding multiple numbers, you can add them in any order due to the associative and commutative properties of addition!