Page 122 - Dive the Seas and More-2

Coral Reef Teacher’s Guide What and Where are the Coral Reefs?

TEMPTING TENTACLE PROBLEMS

(GRADES 3‐5)

REMEMBER! Hard coral polyps have tentacles in multiples of six.
Soft coral polyps (octocorals) have eight tentacles.

1. There was once an awesome colony of hard corals on a reef in the Pacific Ocean. Each
coral polyp in the colony had 12 tentacles. A very hungry parrotfish swam up and quickly
munched down 30 coral polyps. How many tentacles did the parrotfish munch if he ate
every tentacle on the 30 polyps?

2. A beautiful soft coral swayed gracefully in the water. Along came a boat that dropped its
anchor on the soft coral. Sadly, 2,000 coral polyps had their tentacles crushed. How
many tentacles were crushed by the careless anchor?

3. A huge hurricane brought rains that smashed into a coral reef. Many corals were crushed
by the storm. After the storm was over, only one hard coral with 150 polyps and one
soft coral with 90 polyps survived. Each hard coral polyp that survived had six tentacles.
If all the surviving hard and soft coral polyps have all of their tentacles, how many
total ten- tacles survived the storm?

4. The crown-of-thorns sea star is a main predator on hard corals. One day a crown-of-
thorns busily ate three colonies of hard coral. Each colony had 1,000 polyps. Each polyp
had six tentacles. How many tentacles did the crown-of-thorns sea star eat?

NAME:

E - 10