But because initially when we add a substrate, this quantity is so much smaller than this quantity because very little of that substrate is actually bound onto the substrate, if this is very small compared to this, then this by itself is approximately equal to this. For example, if this is, let's say, 1 million and this is, let's say 999,999, then this is very small and this is approximately equal to this. And so that's where we get this result. And so what that means is in equation five, we can leave as it is what's up with this marker? One moment. Okay, so based on six, what that means is we can leave this S as it is because initially at the beginning, the total concentration of S as total is equal to the concentration of S that is not bound to the enzyme because this quantity is very, very small.