how many beads are on the necklace?

Question

Melanie made a circular necklace. She puts beads evenly spaced around the necklace. If the 4th bead is directly across from the 11th bead, how many beads are on the necklace?

Answer 1

Abi, draw the necklace on a piece of paper. Draw a bead with the number 4. Draw a bunch more beads on the RIGHT side of the page, and number them until you get to 11. How many beads did you add? (I mean, how many beads are there, not counting 4 or 11?)

 

The instructions say it is a circular necklace, and 11 is directly opposite 4. So add some more beads after 11, on the LEFT side of the page, the same number of beads that you added before. Start labeling the ones before 4. Label them 3, 2, and 1. Now label the other ones, starting after 11.

 

When they’re all labelled, what’s the highest number?