diff --git a/_freeze/materials/slides_8a/execute-results/html.json b/_freeze/materials/slides_8a/execute-results/html.json
index 575b35e..438aa92 100644
--- a/_freeze/materials/slides_8a/execute-results/html.json
+++ b/_freeze/materials/slides_8a/execute-results/html.json
@@ -1,8 +1,8 @@
 {
-  "hash": "fdb4f0f74cdcc590cde0d406431964af",
+  "hash": "ec0794e20d6db80f46198eb743b36bd2",
   "result": {
     "engine": "knitr",
-    "markdown": "---\ntitle: \"Intro to Data Science\"\nauthor: \"Lecture 8 -- Custom Functions\"\nengine: knitr\nformat: \n  revealjs: \n    slide-number: c\n    scrollable: false\n    code-overflow: wrap\n    code-line-numbers: false\n    code-copy: hover\n    theme: [night, slides.scss]\n    reference-location: document\n    footer: \"[Programming in R for Biologists](https://njlyon0.github.io/teach_r-for-biologists/)\"\n---\n\n\n## A Guide to Your Process\n\n### [Scheduling]{.blue}\n\n### [Learning Objectives]{.purple}\n\n### [Practice]{.pink}\n\n### [Supporting Information]{.orange}\n\n### [Class Discussion]{.gold}\n\n## [Today's Plan]{.blue}\n\n- Muddiest Point Review\n- Custom Functions\n- Free Work\n\n## [Today's Learning Objectives]{.purple}\n\nAfter today's session you will be able to:\n\n. . .\n\n- Describe the process of writing a new function\n- Create a custom function to perform arithmetic\n\n## [Muddiest Point Review]{.gold}\n\n- Recurring topics from most recent MPs:\n\n\\\n\n. . . \n\n- What other topic(s) would you like to review?\n\n## [What is a \"Custom Function\"?]{.orange} {.smaller}\n\n- We've been working with functions throughout the course\n    - These functions have come from packages we can install from CRAN\n\n\\\n\n. . .\n\n- However, R _also_ lets you write your own functions!\n\n\\\n\n. . .\n\n- Functions _you_ write are called [custom functions]{.purple}\n\n## [Why Write Functions?]{.orange} {.smaller}\n\n- Rewriting / duplicating anything is _risky_\n    - Chance for human error when you're typing\n    - Typos make each \"copy\" potentially give different results\n\n\\\n\n. . .\n\n- Instead you could write/use a custom function!\n\n\\\n\n. . .\n\n- Functions are a \"single source of truth\"\n    - Something went wrong? Fix the function!\n\n\\\n\n. . .\n\n- Can also share function scripts with friends to make their lives easier\n\n## [Special Syntax Note]{.orange} {.smaller}\n\n- R Uses the following special syntax for creating functions\n    - You have to use the `function` function\n\n\\\n\n. . . \n\n- Example syntax:\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|5|8|10|13\"}\n# Define function name\nmultiply <- function(arg1, arg2){\n  \n  # Multiply the arguments together\n  result <- arg1 * arg2\n  \n  # Return that to the user\n  return(result)\n  \n} # End function operations\n\n# Once created, it can be used!\nmultiply(arg1 = 10, arg2 = 5)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 50\n```\n\n\n:::\n:::\n\n\n. . . \n\n- Looks kind of like a conditional or loop, right?\n\n## [Process of Function Writing]{.purple} {.smaller}\n\n- My tips for success in custom function writing:\n\n. . .\n\n1. Write a normal script that does what you want your function to do\n\n\\\n\n. . .\n\n2. Identify which part(s) of the script you want the function user to specify\n    - These will be the arguments!\n\n\\\n\n. . .\n\n3. Do the special formatting to make R recognize it as a function\n\n\\\n\n. . .\n\n4. Use the function like you would any other!\n\n## [Custom Function Demo]{.gold} {.smaller}\n\n- Let's create a function together for practice!\n\n\\\n\n. . .\n\n- Following my tips:\n    1. Write the script version of the function\n    2. Figure out what the function user should have control over\n    3. Make R consider it a function\n    4. Use our new function!\n\n## [Demo Step 1: Write Script]{.gold} {.smaller}\n\n- Let's make a function that adds two numbers together\n    - Artificially simple, I know, but useful to learn with!\n\n\\\n\n. . .\n\n- We begin by making the script version of our function\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Add two numbers together\n4 + 3\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Demo Step 2: Identify Inputs]{.gold} {.smaller}\n\n- Now we identify what the user of our function should be able to control\n\n\\\n\n. . .\n\n- If the function adds two numbers together, the user:\n    - Should control the [first number]{.orange}\n    - Should control the [second number]{.orange}\n    - Should <u>not</u> control the plus sign\n\n\\\n\n. . .\n\n- Let's replace our numbers with objects\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Make objects\nx <- 4\ny <- 3\n\n# Add two objects together\nx + y\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Demo Step 3: Special Format]{.gold} {.smaller}\n\n- We can now make this a real function!\n\n\\\n\n. . .\n\n- Define the function using special R syntax\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|5|8|9\"}\n# Define function\nplus <- function(x, y){\n  \n  # Add arguments together\n  result <- x + y\n  \n  # Return that\n  return(result)\n}\n```\n:::\n\n\n## [Demo Step 4: Use Function!]{.gold} {.smaller}\n\n- Now that the function exists, we can use it just like any other function\n\n\\\n\n. . .\n\n- Add 4 and 3 together using our new function\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Define function\nplus(x = 4, y = 3)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Write Your Own!]{.pink} {.smaller}\n\n- Write a function that converts pounds (lb) to kilograms (kg)\n    - Formula: (pound / 2.2) = kilograms\n\n\\\n\n- Remember my tips:\n    1. Write it like a normal script\n    2. Replace values a user would change with objects\n    3. Use special R syntax\n    4. Then use the function!\n\n\\\n\n- Let me know when you've finished your function\n    - Or if you need help!\n\n## [Temperature Check]{.purple}\n\n#### How are you Feeling?\n\n<p align=\"center\">\n<img src=\"comics/debugging.png\" alt=\"Comic-style graph depicting someone's emotional state as they debug code (from initial struggle and defeat to eventual triumph)\">\n</p>\n\n## [Argument Defaults]{.orange} {.smaller}\n\n- You can set argument defaults when you create a function\n\n\\\n\n. . .\n\n- Advantage: user doesn't have to specify all arguments\n\n\\\n\n. . .\n\n- How do we do this?\n    - Set it in the `function` _parentheses_!\n\n## [Default Example]{.orange} {.smaller}\n\n- Let's define defaults in our addition function\n\n. . .\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|11\"}\n# Define function\nplus <- function(x = 4, y = 3){\n  \n  # Add arguments together\n  result <- x + y\n  \n  # Return that\n  return(result) }\n```\n:::\n\n\n\\\n\n. . .\n\n- We can then use the function without specifying those arguments\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"false\"}\nplus()\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n\\\n\n. . .\n\n- If the user specifies an argument differently, their input \"wins\"\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"false\"}\nplus(x = 10)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 13\n```\n\n\n:::\n:::\n\n\n## [Make a Default]{.pink} {.smaller}\n\n- Let's revisit your pound to kilogram function\n\n\\\n\n. . .\n\n- Set the default pounds to **175**\n\n\\\n\n. . .\n\n- What happens if you run your function with _nothing_ in the parentheses?\n\n## [Temperature Check]{.purple}\n\n#### How are you Feeling?\n\n<p align=\"center\">\n<img src=\"comics/debugging.png\" alt=\"Comic-style graph depicting someone's emotional state as they debug code (from initial struggle and defeat to eventual triumph)\">\n</p>\n\n## [Upcoming Due Dates]{.blue} {.smaller}\n\n### Due before 7/22\n\n#### (By midnight)\n\n- Final deadline for **_all_** work from a summer course\n    - Homework \\#8\n    - GitHub Presence evaluation\n    - _Optional_ [3^rd^ draft]{.pink} of Function Tutorials\n\n## [Free Work]{.gold} {.smaller}\n\n\n- Everything is due at the end of course (_soon!_)\n\n\\\n\nTips for success:\n\n. . .\n\n1. Check out rubrics and make sure you don't miss any \"easy\" points\n\n. . .\n\n2. Don't leave after this slide!\n\n. . .\n\n3. If you have questions, **ask them _now_** during this free work time\n",
+    "markdown": "---\ntitle: \"Intro to Data Science\"\nauthor: \"Lecture 8 -- Custom Functions\"\nengine: knitr\nformat: \n  revealjs: \n    slide-number: c\n    scrollable: false\n    code-overflow: wrap\n    code-line-numbers: false\n    code-copy: hover\n    theme: [night, slides.scss]\n    reference-location: document\n    footer: \"[Programming in R for Biologists](https://njlyon0.github.io/teach_r-for-biologists/)\"\n---\n\n\n## A Guide to Your Process\n\n### [Scheduling]{.blue}\n\n### [Learning Objectives]{.purple}\n\n### [Practice]{.pink}\n\n### [Supporting Information]{.orange}\n\n### [Class Discussion]{.gold}\n\n## [Today's Plan]{.blue}\n\n- Muddiest Point Review\n- Custom Functions\n- Free Work\n\n## [Today's Learning Objectives]{.purple}\n\nAfter today's session you will be able to:\n\n. . .\n\n- Describe the process of writing a new function\n- Create a custom function to perform arithmetic\n\n## [Muddiest Point Review]{.gold}\n\n- Recurring topics from most recent MPs:\n\n\\\n\n. . . \n\n- What other topic(s) would you like to review?\n\n## [What is a \"Custom Function\"?]{.orange} {.smaller}\n\n- We've been working with functions throughout the course\n    - These functions have come from packages we can install from CRAN\n\n\\\n\n. . .\n\n- However, R _also_ lets you write your own functions!\n\n\\\n\n. . .\n\n- Functions _you_ write are called [custom functions]{.purple}\n\n## [Why Write Functions?]{.orange} {.smaller}\n\n- Rewriting / duplicating anything is _risky_\n    - Chance for human error when you're typing\n    - Typos make each \"copy\" potentially give different results\n\n\\\n\n. . .\n\n- Instead you could write/use a custom function!\n\n\\\n\n. . .\n\n- Functions are a \"single source of truth\"\n    - Something went wrong? Fix the function!\n\n\\\n\n. . .\n\n- Can also share function scripts with friends to make their lives easier\n\n## [Special Syntax Note]{.orange} {.smaller}\n\n- R Uses the following special syntax for creating functions\n    - You have to use the `function` function\n\n\\\n\n. . . \n\n- Example syntax:\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|5|8|10|13\"}\n# Define function name\nmultiply <- function(arg1, arg2){\n  \n  # Multiply the arguments together\n  result <- arg1 * arg2\n  \n  # Return that to the user\n  return(result)\n  \n} # End function operations\n\n# Once created, it can be used!\nmultiply(arg1 = 10, arg2 = 5)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 50\n```\n\n\n:::\n:::\n\n\n. . . \n\n- Looks kind of like a conditional or loop, right?\n\n## [Process of Function Writing]{.purple} {.smaller}\n\n- My tips for success in custom function writing:\n\n. . .\n\n1. Write a normal script that does what you want your function to do\n\n\\\n\n. . .\n\n2. Identify which part(s) of the script you want the function user to specify\n    - These will be the arguments!\n\n\\\n\n. . .\n\n3. Do the special formatting to make R recognize it as a function\n\n\\\n\n. . .\n\n4. Use the function like you would any other!\n\n## [Custom Function Demo]{.gold} {.smaller}\n\n- Let's create a function together for practice!\n\n\\\n\n. . .\n\n- Following my tips:\n    1. Write the script version of the function\n    2. Figure out what the function user should have control over\n    3. Make R consider it a function\n    4. Use our new function!\n\n## [Demo Step 1: Write Script]{.gold} {.smaller}\n\n- Let's make a function that adds two numbers together\n    - Artificially simple, I know, but useful to learn with!\n\n\\\n\n. . .\n\n- We begin by making the script version of our function\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Add two numbers together\n4 + 3\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Demo Step 2: Identify Inputs]{.gold} {.smaller}\n\n- Now we identify what the user of our function should be able to control\n\n\\\n\n. . .\n\n- If the function adds two numbers together, the user:\n    - Should control the [first number]{.orange}\n    - Should control the [second number]{.orange}\n    - Should <u>not</u> control the plus sign\n\n\\\n\n. . .\n\n- Let's replace our numbers with objects\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Make objects\nx <- 4\ny <- 3\n\n# Add two objects together\nx + y\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Demo Step 3: Special Format]{.gold} {.smaller}\n\n- We can now make this a real function!\n\n\\\n\n. . .\n\n- Define the function using special R syntax\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|5|8|9\"}\n# Define function\nplus <- function(x, y){\n  \n  # Add arguments together\n  result <- x + y\n  \n  # Return that\n  return(result)\n}\n```\n:::\n\n\n## [Demo Step 4: Use Function!]{.gold} {.smaller}\n\n- Now that the function exists, we can use it just like any other function\n\n\\\n\n. . .\n\n- Add 4 and 3 together using our new function\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"true\"}\n# Define function\nplus(x = 4, y = 3)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n## [Write Your Own!]{.pink} {.smaller}\n\n- Write a function that converts pounds (lb) to kilograms (kg)\n    - Formula: (pound / 2.2) = kilograms\n\n\\\n\n- Remember my tips:\n    1. Write it like a normal script\n    2. Replace values a user would change with objects\n    3. Use special R syntax\n    4. Then use the function!\n\n\\\n\n- Let me know when you've finished your function\n    - Or if you need help!\n\n## [Temperature Check]{.purple}\n\n#### How are you Feeling?\n\n<p align=\"center\">\n<img src=\"comics/debugging.png\" alt=\"Comic-style graph depicting someone's emotional state as they debug code (from initial struggle and defeat to eventual triumph)\">\n</p>\n\n## [Argument Defaults]{.orange} {.smaller}\n\n- You can set argument defaults when you create a function\n\n\\\n\n. . .\n\n- Advantage: user doesn't have to specify all arguments\n\n\\\n\n. . .\n\n- How do we do this?\n    - Set it in the `function` _parentheses_!\n\n## [Default Example]{.orange} {.smaller}\n\n- Let's define defaults in our addition function\n\n. . .\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"|2|11\"}\n# Define function\nplus <- function(x = 4, y = 3){\n  \n  # Add arguments together\n  result <- x + y\n  \n  # Return that\n  return(result) }\n```\n:::\n\n\n\\\n\n. . .\n\n- We can then use the function without specifying those arguments\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"false\"}\nplus()\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 7\n```\n\n\n:::\n:::\n\n\n\\\n\n. . .\n\n- If the user specifies an argument differently, their input \"wins\"\n\n\n::: {.cell}\n\n```{.r .cell-code  code-line-numbers=\"false\"}\nplus(x = 10)\n```\n\n::: {.cell-output .cell-output-stdout}\n\n```\n[1] 13\n```\n\n\n:::\n:::\n\n\n## [Make a Default]{.pink} {.smaller}\n\n- Let's revisit your pound to kilogram function\n\n\\\n\n. . .\n\n- Set the default pounds to **175**\n\n\\\n\n. . .\n\n- What happens if you run your function with _nothing_ in the parentheses?\n\n## [Temperature Check]{.purple}\n\n#### How are you Feeling?\n\n<p align=\"center\">\n<img src=\"comics/debugging.png\" alt=\"Comic-style graph depicting someone's emotional state as they debug code (from initial struggle and defeat to eventual triumph)\">\n</p>\n\n## [My Goal for You]{.purple}\n\n#### From [Lecture 1]{.blue}!\n\n<p align=\"center\">\n<img src=\"comics/r-knowledge.png\" alt=\"Comic-style graph depicting someone's confidence with R changing over time\">\n</p>\n\n## [Your Accomplishments]{.gold} {.smaller}\n\n- In this class, [**you**]{.pink} have done the following:\n    - Made and manipulated data\n    - Created R scripts and RMarkdown reports\n    - Explored version control & GitHub\n    - Performed statistical tests\n    - Written loops and your own custom function(s)\n    - And so much more!\n\n\\\n\n. . .\n\n- If you have a CV/resume, definitely add:\n    - Some (or all!) of these skills\n    - Link to your GitHub profile\n\n## [Closing Thoughts]{.gold} {.smaller}\n\n- I had a lot of fun this summer with y'all!\n\n\\\n\n. . .\n\n- Your development as data scientists has been _amazing_ to witness\n\n\\\n\n. . .\n\n- I particularly loved how you all engaged with the Function Tutorials\n    - You really made it your own\n    - Found the intersection of your interests and R functions\n\n\\\n\n. . .\n\n- Do you have any last R / data things to discuss?\n\n## [Upcoming Due Dates]{.blue} {.smaller}\n\n### Due before 7/22\n\n#### (By midnight)\n\n- Final deadline for **_all_** work from a summer course\n    - Homework \\#8\n    - GitHub Presence evaluation\n    - _Optional_ [3^rd^ draft]{.pink} of Function Tutorials\n\n## [Free Work]{.gold} {.smaller}\n\n\n- Everything is due at the end of course (_soon!_)\n\n\\\n\nTips for success:\n\n. . .\n\n1. Check out rubrics and make sure you don't miss any \"easy\" points\n\n. . .\n\n2. Don't leave after this slide!\n\n. . .\n\n3. If you have questions, **ask them _now_** during this free work time\n",
     "supporting": [],
     "filters": [
       "rmarkdown/pagebreak.lua"
diff --git a/materials/slides_8a.qmd b/materials/slides_8a.qmd
index 5a8f9b1..1d62034 100644
--- a/materials/slides_8a.qmd
+++ b/materials/slides_8a.qmd
@@ -373,6 +373,56 @@ plus(x = 10)
 <img src="comics/debugging.png" alt="Comic-style graph depicting someone's emotional state as they debug code (from initial struggle and defeat to eventual triumph)">
 </p>
 
+## [My Goal for You]{.purple}
+
+#### From [Lecture 1]{.blue}!
+
+<p align="center">
+<img src="comics/r-knowledge.png" alt="Comic-style graph depicting someone's confidence with R changing over time">
+</p>
+
+## [Your Accomplishments]{.gold} {.smaller}
+
+- In this class, [**you**]{.pink} have done the following:
+    - Made and manipulated data
+    - Created R scripts and RMarkdown reports
+    - Explored version control & GitHub
+    - Performed statistical tests
+    - Written loops and your own custom function(s)
+    - And so much more!
+
+\
+
+. . .
+
+- If you have a CV/resume, definitely add:
+    - Some (or all!) of these skills
+    - Link to your GitHub profile
+
+## [Closing Thoughts]{.gold} {.smaller}
+
+- I had a lot of fun this summer with y'all!
+
+\
+
+. . .
+
+- Your development as data scientists has been _amazing_ to witness
+
+\
+
+. . .
+
+- I particularly loved how you all engaged with the Function Tutorials
+    - You really made it your own
+    - Found the intersection of your interests and R functions
+
+\
+
+. . .
+
+- Do you have any last R / data things to discuss?
+
 ## [Upcoming Due Dates]{.blue} {.smaller}
 
 ### Due before 7/22