Students will learn how to evaluate a function from it's graph. That is, students will be given an \(x\) value and asked to find \(f(x).\) The function may be continuous or discrete. Here's a video for continuous functions and here's one for discrete. Students can practice here.
Next, give your students these challenges:
Different Deductions by NRICH: Here's how I solved this puzzle: Look at the first column and third column, they are the same, except the first column contains a triangle in the first row, while the third column contains a square in the first row. This tells us we have to find how the value of the triangle and square differ. But have a look at the third and fourth rows. They only differ in that one contains a triangle while the other contains a square. But the sum of these rows is known, so from this, we deduce the value of the triangle is 2 less than the value of the square. Thus, the sum of the first column must be 2 less than the sum of the third column. So our answer must be 23 - 2 = 21. You could also solve this puzzle by determining the value of each shape, but as I've just shown, this isn't necessary.
Conclude by leading this investigation:
Venus Flytrap – dangerous decimals