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About Time (Updated!)

How has the pace of innovation changed over human history?

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About Time (Updated!)

How has the pace of innovation changed over human history?

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Check it out! This lesson was just updated in September 2024, and we hope you love the new and improved version. If you've already prepped an earlier version, fear not, you can still find those here through Thursday December 5, 2024.

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About Time - Student Handout.pdf
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About Time - Teacher Guide.pdf
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2023-2024 Versions

In the fall of 2024, Citizen Math released updated versions of every lesson in our library, plus a few new ones! We know you may have already prepped an earlier version or planned a repeat of last year, so we're continuing to make these earlier versions available through Thursday December 5, 2024.

You can find the new lessons through the regular search, and we hope you love them as much as we do. You can read more about these updates in Our Community.

How has the pace of human innovation changed over time? It took 260,000 years for humans to go from the spear to the bow-and-arrow, but only 42,000 years to go from the bow-and-arrow to the atomic bomb.

Students order and subtract integers to explore major milestones in human history and debate whether humans are innovating faster than we can keep up with the consequences.

REAL WORLD TAKEAWAYS

  • Humans have been making technological innovations throughout history – in communication, in travel, in warfare. Over time, advancements from one milestone to the next have come more and more quickly.
  • Future innovations – like those of the past – will likely offer convenience and meaningful enhancements to our lives; they may also come with serious dangers. It’s important for society to anticipate, consider, and discuss these impending risks.

MATH OBJECTIVES

  • Model “before zero” years using negative integers
  • Order and position positive and negative integers on a number line
  • Find the difference between integers, including negatives
Appropriate most times as students are developing conceptual understanding.
Grade 7
Rational Numbers
Grade 7
Rational Numbers
Content Standards 7.NS.1 Apply and extend previous understandings of addition and subtraction to add and subtract rational numbers; represent addition and subtraction on a horizontal or vertical number line diagram. (a) Describe situations in which opposite quantities combine to make 0. For example, a hydrogen atom has 0 charge because its two constituents are oppositely charged. (b) Understand p + q as the number located a distance |q| from p, in the positive or negative direction depending on whether q is positive or negative. Show that a number and its opposite have a sum of 0 (are additive inverses). Interpret sums of rational numbers by describing real-world contexts. (c) Understand subtraction of rational numbers as adding the additive inverse, p — q = p + (‐q). Show that the distance between two rational numbers on the number line is the absolute value of their difference, and apply this principle in real-world contexts. (d) Apply properties of operations as strategies to add and subtract rational numbers. 7.NS.3 Solve real-world and mathematical problems involving the four operations with rational numbers.
Mathematical Practices MP.2 Reason abstractly and quantitatively. MP.3 Construct viable arguments and critique the reasoning of others. MP.4 Model with mathematics. MP.5 Use appropriate tools strategically.

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Percents & Proportions
Appropriate most times as students are developing conceptual understanding.

Big Foot Conspiracy (Updated!)

Should people with small feet pay less for shoes?

Grade 7
Ratios & Proportions
Great anytime, including at the beginning of a unit before students have any formal introduction to the topic.

Common Cents (Updated!)

Should the United States get rid of the penny?

Grade 7
Rational Numbers
Appropriate most times as students are developing conceptual understanding.

To Have and to Hold (Updated!)

Is renting a storage unit a good idea?

Grade 7
Equations & Expressions
Appropriate most times as students are developing conceptual understanding.

Axle Roads (Updated!)

How do vehicles turn so smoothly?

Grade 7
Measuring Circles
Appropriate most times as students are developing conceptual understanding.

Grading Scales of Justice (Updated!)

What’s the best grading policy?

Grade 7
Percents & Proportions
Appropriate most times as students are developing conceptual understanding.