Geometry and spatial reasoning Activity 4.10 Connections to the mathematics TEKS (4.10) The student recognizes the connection between numbers and their properties, and points on a line. The student is expected to locate and name points on a number line using whole numbers, fractions such as halves and fourths, and decimals such as tenths. Students work in groups of four. Each student is given a transparency with a number line printed on it. The locations for 0 and 1 are marked, but nothing else. One student 0 1 records whole numbers on one transparency, one student records halves ( 2 , 2 , 22 , 3 , etc.), one student records fourths ( 04 , 41 , 24 , etc.), and one student records decimals 2 (0.0, 0.1, 0.2, 0.3, 0.4, etc.). The students place their transparencies on top of one another, staggered so that the number lines appear as shown below: 1 0 0 0 1/2 1/4 0 2/4 2/2 3/4 4/4 1.0 0.5 Students compare the number lines and identify equivalent fractions and decimals that name the same points on the number line. Questioning... Open with... Describe your number line. Probe further with... • How did you decide where to place the halves? • How did you decide where to place the fourths? • How did you decide where to place the decimals? 1 • What other numbers are equal to ? Equal to 1? Equal to 1.5? Equal to 2? 2 • What patterns do you notice? 140 Chapter 2 – Grade 4 Geometry and spatial reasoning Listen for... • Does the student use mathematical vocabulary such as five-tenths, threehalves, or equals? • Does the student notice patterns and relationships? (For example, one-fourth is between zero and one-half.) Look for... • Is the student’s number line accurate? • How does the student determine fractional parts? (folding, measuring, estimating) • Does the student use mathematical notation to label points on the number line? • Is the student able to self-correct errors as the transparencies are placed on top of one another? Chapter 2 – Grade 4 141