ElevateK12- 06-11-2025

By Antoinette Norris Woodson

​ 🧠 Today's Agenda

• 🎮 Log in to Quizizz Class

• 🍎 Learn what “substitution” means using food

• 🍊 Solve a fruit puzzle with substitution

• 🏀 Solve a real-world sports card problem

• 🎉 Play a quick game to test what you know

Draw

Crack the code! 🕵️‍♀️ Figure out how much

each food is worth using the clues.

Then swap in the numbers to solve the

final mystery equation!

Please write your thinking on the screen

​🎉 Welcome! Let’s Get Ready to Learn 🎉

1. Visit: https://quizizz.com/join/class

2. Log in or create a free account

3. Enter Class Code: Y132438

​💬We’ll play a quick game at the end of class—go ahead and join now so you’re ready!

Poll

Have you ever traded BBQ dip for honey mustard?
Or swapped chocolate milk for white milk at lunch?

Or switched your fries for tater tots?

Or exchange one item for another item?

• Yes

• No

In math, we do the same thing!


We substitute a value for a variable (letter) to help us solve a problem.

💬 Substitution just means replacing one thing with another to make it easier.

​That’s substitution!

​🎛Let's Walk Through the Process

• Some are basketball 🏀

• Some are baseball ⚾

• He earned $800 by selling all the cards

• Each basketball card is worth $20

• Each baseball card is worth $15

Desmond has 40 sports cards

Desmond’s Sports Card Collection💪

1st We assign variables:

• k = number of basketball cards

  each basketball card is worth $20

• s = number of baseball cards

  each baseball card is worth $15

2nd We write our Equations:

• k + s = 40 🏀+ ⚾= 40

• 20k + 15s = 800 20🏀+ 15⚾= 800

Let’s break this down step by step!

🏀 Define & Write the Equations

Let's begin with the first equation:

Start with the first equation:
➡️ k + s = 40

-k -k
s = 40 - k

➡️ Solve for s:
 s = 40 - k ⚾= 40 - 🏀

Let’s break this down step by step!

🏀Let’s Solve with Substitution

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Now we solve for s:
➡️ s = 40 - 40 = 0

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Now we solve for s: s = 40 - k
➡️ s = 40 - 40 = 0 substitute 40 for k

✅ Final Answer:
Desmond had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Now we solve for s: s = 40 - k
➡️ s = 40 - 40 = 0 substitute 40 for k

✅ Final Answer:
Marcus had 40 basketball cards and 0 baseball cards.

​

Remember:
s = 40 - k
⚾= 40 - 🏀

Now substitute s into the second equation

Let’s break this down step by step!

🏀Let’s Solve with Substitution

​➡️ 20k + 15(40 - k) = 800 reminder: (15⋅40 - 15⋅k) = 600 - 15k
➡️ 20k + 600 - 15k = 800 combine 20k - 15k
➡️ 5k + 600 = 800 subtract 600 from both sides
➡️ 5k = 200 divide both sides by 5
➡️ k = 40

Then solve for s:
➡️ s = 40 - 40 = 0 substitute 40 for k

✅ Final Answer:
Desmond had 40 basketball cards and 0 baseball cards.

​Help! The Steps Are Scrambled!

On the next slide, the steps are out of order. Use what you’ve learned to put them in the correct order. If you get stuck, use the video to help you.

Reorder

Here are the steps for solving a substitution problem.

The steps are out of order!

Can you put them in the correct sequence?

Need help? Use the video to help you.

• Write both equations

• Replace one variable using substitution

• Substitute the expression into the other equation

• Solve the equation

• Solve for the second variable

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Poll

What is your level of confidence of today's lesson?

Productive Practice

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