In this lesson, we’ll introduce the concept of benchmark percents to `6`th graders with double number lines to find a variety of benchmark percents for a given value. Students will start the lesson with a review on double number lines and how to use them which will help students to move into the benchmark activity.
ByteLearn gives students targeted feedback and hints based on their specific mistakes
Students will be able to find benchmark percentages from a number.
Start the class with a quick warm-up activity on reviewing double number lines. You can present this slide on the screen and ask students to come up and fill in the missing boxes - each student gets to fill in one. They have to explain their rationale as they fill in a box.
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Explain to students that they will be using a double number line to find benchmark percentages. The next two slides works with deciles. Ask students to work in pairs to fill the missing boxes. These number lines can be found in the Deciles and Quartiles Number lines document.
Ask students to share their strategy for filling in the missing boxes. Asking for `100%` and `0%` helps to reinforce these ideas which we might assume that students know. Finding `10%` by dividing the whole by `10` makes it a lot easier to find other percentages that are multiples of `10`. In slide `4`, we ask for `20%` - ask them why might we find `20%` instead of `10%`.
Build on this number line. Ask students to write down their answer for `5%` of `140`. Follow that with `105%` of `140`. Make sure to call students to the board to locate `5%` and `105%` on the number line. Follow that with `170%` of `140`. This will help students to get comfortable with percents beyond `100%`.
Work through the next few slides with students on `10%` and `25%` benchmarks. Remind students that they should always fill in the values for `0%` and `100%` of the given number first.
It is fascinating to see the different ways in which students arrive at the answers for this number line. Some might choose to go to `25%`, then `50%` and then `75%` while some might want to start with `50%` first. There are at least three different ways in which students find `75%`
Let students know that they can use double number lines to find benchmark percents with word problems as well. Provide students with the Partner Activity Worksheet and allow students to work together. This worksheet introduces word problems and how to go about solving them. This worksheet also uses both `10%` and `25%` intervals for students to practice with.
Go over the answers as a class and discuss. You can use the last two slides to go over the worksheet. You may choose a group to create the second double number line on the board.
After students have completed their lesson, it’s time for some independent practice! ByteLearn gives you access to tons of benchmark percent activities. Check out the online practice and assign to your students for classwork and/or homework!
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