Are these correct?

two more than a number and four =
2 + n + 4

ten more than a number plus 3 =
n + 10 + 3

three increased by a number minus 5 =
n + 3 - 5

six and a number decreased by 7 =
n+6-7

These look right.

To assess whether the given expressions are correct, let's break them down and simplify them:

1. Two more than a number and four:
The expression is 2 + n + 4. This can be simplified by combining like terms:
2 + n + 4 = (2 + 4) + n = 6 + n

2. Ten more than a number plus three:
The expression is n + 10 + 3. Simplifying this expression:
n + 10 + 3 = n + (10 + 3) = n + 13

3. Three increased by a number minus five:
The expression is n + 3 - 5. Simplifying this expression:
n + 3 - 5 = n + (3 - 5) = n - 2

4. Six and a number decreased by seven:
The expression is n + 6 - 7. Simplifying this expression:
n + 6 - 7 = (n + 6) - 7 = n - 1

Therefore, the given expressions are correct and can be simplified as follows:
1. Two more than a number and four = 6 + n
2. Ten more than a number plus three = n + 13
3. Three increased by a number minus five = n - 2
4. Six and a number decreased by seven = n - 1