Increase/Decrease and How Much?
Lesson 6 of 17
Objective: SWBAT calculate percent of change (% increase and decrease) and review other percent and proportional relationship topics.
Do Now – Speed Test
Students enter silently according to the Daily Entrance Routine. Their Do Now assignments are already on their desk and they begin working silently. They are turned over to the blank side and as students file in they are asked NOT to turn the papers over. There is a timer displayed on the SmartBoard with 3 minutes set. I ask all students to write their name on the blank side of the paper. This helps me collect papers quickly at the end of the sprint without having to wait for students to write their name on their paper (or wonder if they are adding or correcting answers). Once all students are ready with pencils in hand, I say “ready, set, go!” and students race to complete each percent fluency question on their paper.
Note* These sprints are created from materials on the NY State education site, www.engageny.org
At the end of 3 minutes, I ask all students to raise their pencils in the air and count the number of problems they completed. If they complete 35 problems or more (80% of the sheet) they may submit their paper for achievement points in a determined basket in the room. I set the timer with 20 seconds letting students know this is when I need everyone back in their seat.
While students are submitting their papers I select another to help me pass back graded sprints from previous days. Students earn achievement points based on the number of completed items and the percent correct of those completed. A couple of students are achieving 100% completion and 100% correct. These students are celebrated whole class (i.e. “let’s give two claps for…”) once everyone is seated.
Students are given a copy of the “Class Notes” for today. They must fill out the heading and copy the aim off the board. The worksheet attached includes a copy for the instructor. The red font indicates writing to be completed by students. The definitions below are written on the board for students to copy:
- Percent change: A ratio that compares the change in a quantity to the original amount.
- Percent increase: the ratio (fraction) of an amount of decrease to the original amount, calculated as a percent
- Percent increase: the ratio (fraction) of an amount of increase to the original amount, calculated as a percent
We also review “percent of” problems, which many students struggled to master the previous day. I demonstrate the strategy shown below:
Task – Percent Maze
Students will need to complete a Math Maze by completing 15 problems from three different sections of a “maze”. I’ve divided the room into three sections to travel around as students complete three different fluency skills related to percent application problems (proportional reasoning, percent change, percent of ).
Part 1: Proportions
Students must solve 5 problems from this sheet (10 total). One of these 5 must include #1, 4, or 5. Students must raise their hand when they’re ready for me to check. Each time I check a student’s paper I’m looking for work shown in the form of proportions and their solutions. The required problems (#s 1, 4 and 5) require the use of parentheses and the distributive property. The video below shows the way I review the application of this skill.
Part 2: Percent of
Students move to the next designated part of the room, picking up a new worksheet from a basket at the front of the room. They are to complete 5 problems from this sheet, using bar models or the new strategy learned in the notes.
Part 3: Percent change
Students may work at booths on the last worksheet of the class work. These problems require students to calculate and state the percent increase/decrease.
Students share out the most difficult questions that I can review with them and take the task home to complete for homework.
Through student or teacher questions, I need to know:
- how many students still cannot convert fractions to decimals? This list will be used for my remediation period in the day.
- how many still do not understand percent increase/decrease?
- can students solve proportions? including the examples required in the grade
Knowing the answers to these questions will help determine if this lesson needs to be retaught or reviewed in small groups this week.