Turning an Equation into a Graph — My Students’ Lightbulb Moment
Recently, I taught my Year 9 class how to plot a simple linear equation , and it turned into one of those lessons where you could see the lightbulbs go on ๐ก. Our equation for the day was: ๐ y = 2x + 1 At first, a few learners struggled to remember that in coordinates we always plot x first, then y — as in (x : y) . We drilled that into memory with a quick chant: “X comes before Y — just like in the alphabet!” ๐ ๐งฎ Step 1: Understanding the Equation We started by unpacking what the equation tells us. For every value of x , we can calculate a value for y . So, I gave them a simple table and we chose easy x-values like 0, 1, 2, 3, 4. I explained that x = 0 is extra special — it shows us the y-intercept , where the line crosses the y-axis. ⚙️ Step 2: Using the “Function Machine” To make it fun, we used a little function machine idea. You “feed” x into the machine, multiply it by 2, then add 1. Out pops your y-value! This visual really helps students who need to see h...