Lesson: One Cool Kid

Display the inequality symbols <, >, ≤, and ≥. Then ask: What words or phrases might you see in a word problem that would lead you to answer using one of these symbols? Write the words or phrases students give underneath the appropriate symbol. Some responses might include: more than, less than, at most, at least, no more than, no less than, greater than or equal to, less than or equal to, etc. Tell students that they will be learning how to write and graph inequalities in today’s lesson.

Tell students that they are going to read about a girl named Gitanjali Rao who invented a device that detects lead in water. Play the video and ask students to think about the following questions while they watch:
• How is Gitanjali’s invention more efficient than other lead detection tests?
• What did Gitanjali learn while touring Denver Water?
• What information did you find new and interesting?

Distribute or digitally share the “Problem and Solution” literacy skills sheet and read the introduction aloud. Tell students that Gitanjali’s device, Tethys, helps solve a number of problems mentioned in the article. Students can use these or any other problems they find in the article to fill in their skills sheet. Allow students to work in pairs to read the article and complete their sheets. Then have volunteers share examples of the problems and solutions they found.

Give students note cards or allow them to create digital sticky notes before beginning the video. Tell them that there are some helpful reminders they may want to write down that can be used later on in the lesson. Then play the instructional video for students. Allow students to take notes as they see fit on their cards. To prompt students to record important information, pause at the following points in the video: 1:15, 1:32, 2:45.

Read through the “Writing and Graphing Inequalities” box on page 23. Have students compare the word clues they brainstormed with what is listed in the article. Ask: What is different between the greater-than graph and the greater-than-or-equal-to graph? Why might this difference exist? (The greater-than graph has an open circle. The greater-than-or-equal-to graph has a closed circle. This is because with greater-than-or-equal-to inequalities, the circled point on the line is a solution. In greater-than inequalities, the circled point on the line is a marker but not one of the solutions.) Then have a volunteer read question 1 of the “Your Turn” questions aloud. Model marking up the question by highlighting or underlining the word clues “more than 5,000.” Ask students to identify which inequality symbol would represent more than (>). Then choose a student volunteer to draw a graph of the inequality. Reinforce why the dot should be open and not closed for this problem. Tell students that they can check their work by picking a point on the graph and asking themselves ”Does this chosen point still make the problem true?”

Tell students to imagine that they are a teacher or tutor and they have to create a mini-lesson on inequalities for an elementary student. Have them make a poster, video, or worksheet explaining inequalities, how to write them, and how to graph them.