Graphing in Slope-Intercept Form
I can graph y = mx + b by plotting (0, b) first, then stepping by the slope.
What students learn
Students learn to read m and b from y = mx + b (rewriting it first when needed), plot (0, b), step by the slope to a second point and draw the line.
See inside
The key rule
Plot (0, b) first, then step by m to a second point, and draw the line through both.
start (0, b), then step by m
Step from (0, b), never from the origin unless b = 0.
Watch out
Kim graphs y = 3x + 2 by starting at the origin and stepping up 3, right 1.
The mistake: (0, 0), then (1, 3)That line crosses the y-axis at 0, not at 2.
The fix: (0, 2), then (1, 5)Start at b, then step by m.
The mistakes it targets
- Reads m and b in the order they are written instead of by role
- Steps up for a negative slope
- Drops the sign of b
- Starts the graph at the origin instead of at (0, b)
- Divides only one term when solving for y
The interactive Teacher Deck (32 slides, PowerPoint)
- The Learn page taught on screen: 8 fill-in blanks, each filled on its own click as students write it
- The worked example one slide per step (four steps), each with the reason for the step
- Six practice and three apply problems: a your-turn slide with a think-time bar, then the solution one line per click
- Jump buttons on every slide: go straight to any problem, the answer bank or the exit ticket
- Speaker notes on each problem: the question to ask, the worked answer and the common error to listen for
- A completed deck PDF (19 pages) with every slide fully built, to print or post
The student packet (9 pages)
- Learn: guided notes with four definitions, the key rule, a worked example and a Watch Out error pair
- Practice: two warm-up, two standard and two stretch problems, with an answer bank for self-checking that hides three common-mistake decoys
- Apply: one word problem, a reasoning prompt and one error analysis
- Assess: an exit ticket of four items, two per page, with an I-can self-rating
- Homework (page 5): eight new problems, two warm-up, four standard and two stretch
- Answer key (pages 6–7): every problem worked step by step, four common mistakes with what to do about each, and a grading guide, plus the homework key (page 8)
- Color and ink-saver editions of the whole packet
Standard codes refer to the Common Core State Standards for Mathematics. Math Class 678 is an independent publisher, not affiliated with, sponsored by, or endorsed by NGA Center or CCSSO. Every product is sold on Teachers Pay Teachers.