For the day's Warm Up, I have selected five problems that reflect the previous day's introduction to scientific notation. Students must multiply by powers of 10, circle significant digits of given numbers, and write two numbers in proper scientific notation.
As students work, I move about the room checking for student understanding. A common misconception I notice is students adding zeroes for the exponent instead of moving the decimal.
Once the timer sounds, I select students at random from my cup of name sticks. Those students come to the board to write their answers. I ask for confirmation from the class. If there is disagreement, I ask the student to explain. We continue until we reach consensus on all the answers.
For additional exposure to the previous day's objective, I show a number written in standard form next to the number expressed in scientific notation. I ask for a volunteer to explain the process in a Quick Recap. I am careful to select a student who has demonstrated proficiency on the warm up problems and has strengths in oral communication so that all students hear an effective synopsis. If the student student does not use key vocabulary like 'significant digit' or 'exponent', I ask guiding questions like, "What is the role of the significant digits?". Once the student has completed the explanation, I ask for any additions. I then explain that today, we are going to hone our skills through two activities: practice problems and a cut-and-match activity.
For Let's Practice!, I provide students additional practice in writing numbers in proper scientific notation by giving them 8 problems, 4 with positive exponents and 4 with negative. Typically, I am able to spot misconceptions as students work. One common error is for students to count the leading zero on numbers less than one as significant digits. To correct this, I ask students where the decimal point is and how many times do they need to multiply by ten to move it where it needs to be.
After students have completed the eight practice problems, I pass out an activity page called "sci not cut-and-match". I show a copy of the page (Cut-and-Match) on the Smartboard as I instruct the students to cut out the left column of numbers and glue it in their journals, leaving space for each match on the right. I then explain that they must cut the right column into individual numbers and match them to the corresponding standard form. I encourage students to check each others' work as they continue. This provides an opportunity for a lot of peer sharing and redirecting. As students work, I continue to circulate the room, spot-checking answers and paying close attention to students who have been struggling with the concept.
For closure, I explain that we are going to end class with a quick activity called Take Off and Land. I then show students that as I touch a grey rectangle, a number will be revealed. If the number is written in correct scientific notation, they should stand up. If it is incorrect they should remain seated or sit down.