Curated OER
The Square Counting Shortcut
An excellent lesson plan that encourages students to discover how complex figures can be broken into simpler shapes when measuring area. Working with block letters, learners are given the freedom to develop their own strategies for...
Shodor Education Foundation
Triangle Area
While the lesson focuses on right triangles, this activity offers a great way to practice the area of all triangles through an interactive webpage. The activity begins with the class taking a square paper and cutting in in half; can they...
101 Questions
Best Square
If you're a square, be the best square you can be! Young scholars develop a formula to determine the four points that make the best square that considers the area, perimeter, and other dimensions. They use their formulas to rank attempts...
Curated OER
Estimating the Mean State Area
Seventh grade statisticians randomly select five states and then determine the mean area. The class then works together to create a dot plot of their results.
Illustrative Mathematics
Placing a Square Root on the Number Line
There are many ways to approach finding the rational approximation of an unknown square root. Here is a problem that will help math learners make a connection between square roots and their order on a number line. As usual, determine two...
Illustrative Mathematics
Finding Areas of Polygons, Variation 1
An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...
Curated OER
Finding the Area of Polygons
Third graders are exposed to finding the area of polygons by decomposing figures and recomposing them into rectangles. This strategy allows children to expand on their prior knowledge of constructing shapes by rearranging parts into...
101 Questions
Circle-Square
How do the area and perimeters of circles and squares compare? A clever video illustrates the change in the area of a circle and square while their total perimeter stays the same. The task is for learners to predict the point where the...
101 Questions
Square Partitions
Challenge your classes while developing their problem-solving skills. A square is divided neatly into four equal triangles by its diagonals until one diagonal is moved from a vertex to the midpoint of one side. Now, scholars must devise...
Curated OER
Inscribing a Square in a Circle
Inscribing a square in a circle brings up a number of interesting geometry topics including triangle congruence and how to prove a quadrilateral is a square. This activity is followed up by finding the area of the square and determining...
Curated OER
Unit Squares and Triangles
This is an interesting geometry problem. Given the figure, find the area of a triangle that is created by the intersecting lines. The solution requires one to use what he/she knows about coordinate geometry, as well as triangle and angle...
Illustrative Mathematics
Same Base and Height, Variation 2
This is a good model for learners to visualize triangles of the same base and height. They can can begin to comprehend that these triangles will have the same area no matter how the triangle is drawn. It is part of a series of resources...
Illustrative Mathematics
Converting Square Units
Jada has a rectangle board that is measured in inches. Young learners confirm their understanding of converting inches to feet. Then they find the area in square feet. Jada thinks she has a short-cut to convert inches square to square...
Curated OER
Halves, Thirds, and Sixths
An excellent activity that effectively pulls together the concepts of area, fractions, and equivalent fractions! Using 3x2 rectangular arrays, 3rd graders are introduced to the concept of area in terms of square units. Building on this...
Curated OER
Area of the Lawn Project
Students calculate simple area calculations in real-life situations. They determine simple wage computations. They use critical thinking skills. They demonstrate their ability to use writing in order to express mathematical thoughts and...
Illustrative Mathematics
Equal Area Triangles on the Same Base II
A deceptively simple question setup leads to a number of attack methods and a surprisingly sophisticated solution set in this open-ended problem. Young geometers of different strengths can go about defining the solutions graphically,...
Illustrative Mathematics
Floor Plan
A multi-step problem has learners finding the actual area based on a scale drawing and then converting units at the end. Two different solution choices are listed depending on the preference on which step to start first. Both methods can...
University of Wisconsin
What’s a Square Foot Anyway? Laying Out the Design Plan
Clever! Participants don square-foot cardboard shoes to mark out the rain garden plot that they have spent the last few weeks designing. In this way, they are practicing scale modeling as well! Note that this lesson plan is part of a...
Illustrative Mathematics
Stained Glass
A complex question looking for the total cost of a stained glass window by calculating area and circumference of a circle. With detailed components, this activity will challenge your designers to figure out if they have enough money to...
University of Wisconsin
Sizing a Rain Garden
Most appropriate if you are applying the entire unit to build a rain garden at your school, this installment involves calculating the area that will drain into it. Your garden planners will need data from previous lessons, so this one...
Illustrative Mathematics
Painting a Barn
When painting a barn you have to calculate surface area, and that is exactly what this resource is about. Not only will your future home owners calculate the surface area, but also the cost. It is a real-life problem that every that...
Illustrative Mathematics
Overlapping Squares
The objective of this activity is to find the percent of the area of a two squares overlapping. Mathematicians find the ratio of area for the part that overlaps to the rectangle formed. The final answer is a percent as a rate per 100....
101 Questions
Bubble Wrap
Let your lesson pop by using the resource. After watching a video of a man popping a square piece of bubble wrap, young mathematicians determine the time it would take to pop other pieces of bubble wrap with given dimensions. The...
Under the Dome
The Pythagoras Tree
View a tree designed by Pythagoras. Pupils watch a video as a tree is built by using squares representing the side lengths of a right triangle, with each side of the squares becoming the side of another triangle. Learners come up with...