Warm-up (30 seconds): Think about your Something Real project from Lesson 6. What numbers did you put in your Numbers Sheet? Did you have costs, quantities, or scores?

Recap (30 seconds): Last week you built your Numbers Sheet with real data for your project. Today you'll add formulas to make those numbers tell you something useful.

We'll start with a simple budget example, then you'll add SUM and AVERAGE formulas to your own project Numbers Sheet from Lesson 6.

What formulas do

Formulas are calculations that run automatically whenever the numbers they use change. They always start with = and use cell references like B2 or C5 instead of typing numbers directly.

Why cell references? (not hard-coded numbers)

=B2*C2 uses cell references so when B2 changes from 30 to 50, the result updates automatically. =30*2 would always show 60 even if you change the data.

SUM

=SUM(B2:B6) adds up all numbers in cells B2 through B6. Perfect for total costs, scores, or quantities.

AVERAGE

=AVERAGE(B2:B6) finds the mathematical average (adds them up, then divides by how many there are). Perfect for average cost per item or typical scores.

Live updates

Change any number in B2:B6 and the formula results update instantly.

Portfolio Goal

Your Numbers Sheet (from Lesson 6) becomes a real working budget with totals and averages that answer questions about your Something Real project.

Follow these instructions to add SUM and AVERAGE formulas to a simple example budget. Watch what happens when you change the numbers. You'll learn autofill and horizontal SUMs through hands-on practice.

Your turn: Open your Numbers Sheet from Lesson 6 (in your Digital Portfolio folder). Add SUM and AVERAGE formulas that answer real questions about your Something Real project.

Quick examples for your Lesson 6 sheet:

• Vertical column total: =SUM(C2:C10) adds up all costs in column C
• Horizontal row total: =SUM(B5:E5) adds up all numbers across row 5 for one item's total
• Scores average: =AVERAGE(E2:E10) finds average score in column E

Success criteria:

• At least 2 SUM formulas: One vertical column total (like =SUM(C2:C10)) AND one horizontal row total (like =SUM(B5:E5))
• At least 1 AVERAGE formula: Average cost, average score, average quantity, etc.
• Test the live update: Change one number and confirm all related formulas update
• Clear labels: Every formula result has a label explaining what it calculates

Example questions your formulas should answer:

• What's my total budget? (SUM of costs)
• What's my total income needed? (SUM of targets)
• What's the average cost per item? (AVERAGE of unit costs)

Save as 'Numbers Sheet v2 - Formulas' in your Digital Portfolio folder.