The given expression is $20 \div 5 - 4 + 6$.

To solve this expression, follow the order of operations (PEMDAS):

1. Parentheses
2. Exponents
3. Multiplication and Division (from left to right)
4. Addition and Subtraction (from left to right)

Step-by-step:

1. First, perform the division: $20 \div 5 = 4$
2. Then, proceed with the subtraction: $4 - 4 = 0$
3. Lastly, perform the addition: $0 + 6 = 6$

Thus, the value of the expression is 6.

The correct choice is:

• $\boxed{6}$.

Would you like further explanation on the steps or any specific details?

Here are 5 related questions for practice:

1. What is the result of $48 \div 8 + 6 - 2$?
2. How does the order of operations affect the result of $7 + 3 \times 2$?
3. If an expression has no parentheses, how do you decide what to calculate first?
4. What happens if we change the division in $20 \div 5$ to multiplication?
5. What is the result of $12 + 18 \div 6 - 3$?

Tip: Always remember to handle division and multiplication from left to right before moving to addition and subtraction in a given expression.