Why do this problem?
has potential in several different ways. You could focus on visualisation - asking the children to try and decide whether the patterns are made from more than one piece of string simply by looking.
Alternatively, you could make this a more practical task and encourage your class to recreate the patterns using prepared loops (large elastic bands could be useful perhaps, or bits of ribbon/string/thread tied into loops).
Here is a pdf of the string images which you could print off for the children to use.
Can you explain how you decided on the number of loops there are?
What happens when you choose a starting point and follow the string from there?
Would it help to use a coloured pencil?
Learners could go on to How Many Pieces This Time
Suggest using this sheet
to follow round the pieces of string with a coloured pencil.