Scoring runs of three and four question

I’m a little confused on this rule

Say I’m counting my crib hand and I have 3,4 and 5 in my crib and face up start card is a 6

The same situation could also be for my hand play. (Not pegging round)

Would I be able to score 3 points for a run if 3, 4, and 5 AND four points for a run of 3, 4, 5 and 6 or can I only just score the run of four?

Runs

One run of four is all you get to score. You take the max run (cannot be more than 5) and that is what you get. You CANNOT use the same cards over again in a run. If you use 3, 4, 5 you cannot use them again just by adding another card or two cards. Take the example of a run of 5. Lets say you have 3, 4, 5, 6, 7 in your hand. Using that logic you have a lot of runs. You have (3, 4, 5); (3, 4, 5, 6); (3, 4, 5, 6, 7); (4, 5, 6); (4, 5, 6, 7) and (5, 6, 7). So scoring by using cards over again would have been 25 just for runs and that's not counting any fifteens!

You only score 1 point for

You only score 1 point for each card in the run. So in the hand you describe the 3, 4, 5 and 6 would be worth only 4 points for the straight. You do not get an additional 3 points for the smaller 3 card straights.

You only score 1 point for

You only score 1 point for each card in the run. So in the hand you describe the 3, 4, 5 and 6 would be worth only 4 points for the straight. You do not get an additional 3 points for the smaller 3 card straights.