## Teacher Guide: Lesson 17.7

The Weekly Reader Connections feature on Kids' Place Houghton Mifflin Math provides your students with additional information about the topics that appear in the Curriculum Connection feature in their student books.

The article “Reef Relief” tells students about the need for protecting the world's coral reefs, which suffer from over-fishing, coastal development, and other human activity like pollution. You may wish to point out that corals, which grow only in warm tropical waters, are damaged by a variety of physical impacts, such as anchor damage, accidental boat groundings, and boat propellers. Explain that agricultural runoff–containing pesticides and fertilizers contribute toxins (poisons) to reefs.

You may wish to suggest that much as fish hide in a coral reef, the words in the Word Wise activity word search are “hiding”—waiting to be revealed. Note that although a few of the hidden words are positioned vertically, most of them are positioned “on a slant,” or diagonally.

In the Data Hunt, students learn that the National Aquarium in Baltimore has a coral reef exhibit. Students work with the number of cubic inches of water in 1 gallon to find the volume of the 335,000-gallon tank in cubic inches. Students also find the length of an aquarium tank, given the other two dimensions and the volume of the tank.

1. The volume of 1 gallon of water is about 231 cubic inches. What is the volume of the 335,000-gallon tank in cubic inches? 77,385,000 in.3
2. Suppose an aquarium tank is 20 feet high and 20 feet wide. If it holds 77,385,000 cubic inches of water, how long is the tank? 112 ft