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In this lesson, students review multiplying fractions by whole numbers (5.NF.B.4a) in mathematical and real-world contexts, with the fraction in this case being a percent—a fraction with a denominator of 100. Students thus learn how to determine the percent of a number. Students also practice converting percents into fractions in simplest form. A mental math method of working with percent-of problems is also covered.
Module 1 Video
This video begins with three examples of “value of a number” constructions to show that they all involve multiplication—2 of the boxes, one half of a box, and 30% of a box. A percent is defined as a ratio with a denominator of 100. So, 100% is 100/100, which is equal to 1. Thus, students can use percents like fractions (which are part-to-whole ratios).
Module 2 Video
In this video, students participate in a demonstration of comparing ratios by plotting points on the coordinate plane. Students use plotted ratios for 6 rectangles height-to-length ratios in order to estimate the height-to-length ratio of the original rectangle presented at the beginning of the video.