One Way or the Otter

It feels so nice to float on your back in a pool. Well, sea otters do this all day! These friendly-looking fellows float around in a group called a “raft,” because it really looks like one. The otters hang onto each other and tie themselves together with seaweed, so they won’t drift apart while sleeping. Otters float easily because they have up to 1 million (1,000,000) hairs per square inch! We humans have fewer than 3,000 per square inch – so a lot of us still need floaties.

Wee ones: If a raft has 5 sea otters, what numbers do you say to count them?

Little kids: If that raft of 5 otters meets another raft of 2 otters, how many do they have together?  Bonus: If another raft joins them, how many does that raft need to make a total of 10 otters?

Big kids: If 10 otters are floating and 1/2 of them have all 4 paws in the air, while the other 1/2 each have 1 paw underwater, how many paws are up?  Bonus: If every otter in a 6-otter raft needs to be tied to all the others with 1 piece of kelp, how many pieces of kelp do they need? (Remember not to count doubles between the same 2 otters!)

Wee ones: 1, 2, 3, 4, 5.

Little kids: 7 otters.  Bonus: 3 more otters.

Big kids: 35 paws (20 + 15).  Bonus: 15 pieces. The 1st otter needs 5 pieces to connect to his friends; the next otter needs only 4, since he’s already tied to the 1st otter. The 3rd otter needs just 3, the 4th needs only 2, and the 5th needs just 1. The last otter is already tied to everyone, so he adds none, giving us 5 + 4 + 3 + 2 + 1.

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