Use our present need for cleanliness to engage your students.
Does it really matter whether you kill 99.9% of the bacteria or 99.999% of the germs?
In this 3-act activity we've asked students to consider whether these claims about these two wipes' efficacy really make a difference. We've supplied students with a list of bacteria counts on various surfaces and asked them to calculate how much of a difference these two different percents make in wiping out germs.
This is an excellent opportunity to deal with repeating decimals.
The Activity: KillingGerms-2020.pdf
CCSS: 5.NBT.3, 5.NBT.7, 6.NS.3, 7.NS.2.d, 8.NS.1
For members we have an editable Word docx, an Excel sheet with data and calculations, and solutions.