Substitute Teacher Guide • Grade 9 • Unit 2: Understanding Digital Images

Behind the Image: File Types, Resolution & Visual Hierarchy — Day 2 of 2

Today's focus: Visual Hierarchy & Focal Point

✅ Before Students Arrive

Materials needed today:
- File-format sorting cards (JPG/PNG/TIFF use-case scenarios)
- Printed posters/pages for hierarchy annotation
- Highlighters or colored pencils
Most students keep their class notebook at its usual spot in the room and use it every day (see routine below) -- but it's each student's own notebook, so a few may bring theirs from home instead. Either way, everyone should have one out.
Write today's Do Now on the board before the bell rings (see below).

📓 Daily Notebook Routine (students already know this)

Keep this going every day, in your class notebook: date today's entry, jot your Do Now response, add any new vocabulary word(s) from today's Key Vocabulary section (word + a quick picture + a simple definition in your own words), and take 60 seconds to sketch something connected to today's topic. This notebook is yours to study from, reference on projects, and pull evidence from later for your portfolio.

🗣️ Opening: Do Now

Write or project this, and have students start immediately:

“Which file format is best for print? For the web?”

📋 Class Plan (step by step)

Step 1 — 20 min

🗣️ Say: "Here's what we're doing next." Then read the instructions below to the class.

📋 Annotation activity (20 min): number the order your eye travels across a printed poster/page, from 1 (first) onward, and highlight the focal point.
Step 2 — 8 min

🗣️ Say: "Before the bell, everyone needs to finish the exit ticket."

📋 Exit ticket (8 min).

🔑 Vocabulary Introduced Today

PPI (Pixels Per Inch): The standard designers actually set: images for the web are saved at 72 PPI, images for print at 300 PPI.
Visual Hierarchy: The intentional arrangement of a design so the eye sees the most important information first.
Focal Point: The place in a design where the eye is drawn first.

✅ Wrap-Up: Exit Ticket

A few minutes before the bell, say: "Time to finish your exit ticket."

“Pick one file format from today and explain, in one sentence, why a designer would choose it over the other two.”

Collect exit tickets (or have students leave them in the usual spot) for the regular teacher to review.

⏳ If You're Short on Time

Protect the Do Now and the Exit Ticket above all else -- those are how the regular teacher tracks daily progress. If a step above is optional/homework, or is a "share out"/discussion step, shorten or skip it first.

⏳ If Students Finish Early

Have them keep working in their notebook: add extra detail to today's vocabulary sketch, review previous vocabulary, or -- if this is a portfolio update week for this class -- work on their portfolio. Early finishers should never be idle or distracting to classmates still working.

📝 For the Regular Teacher (fill in ahead of time)

Regular teacher's name / how to reach them: ______________________________
Where finished work / exit tickets go: ______________________________
Front office extension / emergency contact: ______________________________
Anything else this class needs to know today: ______________________________