In the material I'm studying, it says the following;

1. A number sequence is when addition is written horizontally.

2. A number sentence is when subtraction and multiplication are written horizontally.

Is this really specific to addition, subtraction and multiplication, or can they all be interchanged?

Could I say that, 2 + 4 = 6 is a number sentence and that 4 x 5 = 20 is a number sequence?