Mathed Up!
Negative Scale Factor
Class members investigate the effect of a negative scale factor dilation on coordinate shapes as they watch a short video that shows an example of a geometric figure undergoing a dilation with a negative scale factor. Learners then try a...
EngageNY
Scale Factors
Is it bigger, or is it smaller—or maybe it's the same size? Individuals learn to describe enlargements and reductions and quantify the result. Lesson five in the series connects the creation of a dilated image to the result. Pupils...
EngageNY
Solving Area Problems Using Scale Drawings
Calculate the areas of scale drawings until a more efficient method emerges. Pupils find the relationship between the scale factor of a scale drawing and the scale of the areas. They determine the scale of the areas is the square of the...
EngageNY
Computing Actual Lengths from a Scale Drawing
The original drawing is eight units — how big is the scale drawing? Classmates determine the scale percent between a scale drawing and an object to calculate the length of a portion of the object. They use the percent equation to find...
EngageNY
Scale Drawings
Are you searching for a purpose for geometric constructions? Use an engaging approach to explore dilations. Scholars create dilations using a construction method of their choice. As they build their constructed dilation, they...
Mathed Up!
Similar Shapes
Similar shapes are all about the scale. Given seven problems, pupils use scale factors to determine measurements within similar shapes. While solving the problem, scholars also determine whether two figures are similar and use...
EngageNY
The Scaling Principle for Area
As they investigate scaling figures and calculate the resulting areas, groups determine the area of similar figures. They continue to investigate the results when the vertical and horizontal scales are not equal.
EngageNY
Scaling Principle for Volumes
Review the principles of scaling areas and draws a comparison to scaling volumes with a third dimensional measurement. The exercises continue with what happens to the volume if the dimensions are not multiplied by the same...
EngageNY
End-of-Module Assessment Task: Grade 7 Mathematics Module 4
Asses the class to determine their knowledge of proportional relationships involving percents. Class members work through the nine-question assessment with a variety of percent problems. The multi-step problems involve simple interest,...
Flipped Math
Similar Figures
Use some similar problems to find side lengths. Pupils learn the definition of similar figures and how it relates to corresponding angles and sides. Using the definition, individuals calculate the lengths of missing sides and practice...
Corbett Maths
Enlargements Using Ray Method
Figure out what to do when there is no grid to count. Using a ruler and a sharp pencil, the narrator shows how to perform a dilation when the figure is not on a grid. The ray method works by drawing a ray from the center of dilation...
Mathed Up!
Enlargements
Make enlargements with and without centers. Pupils work through seven problems dealing with dilations or enlargements. The first couple items are strict enlargements without centers, while the others have centers. Class members also...
EngageNY
Examples of Dilations
Does it matter how many points to dilate? The resource presents problems of dilating curved figures. Class members find out that not only do they need to dilate several points but the points need to be distributed about the entire curve...
Balanced Assessment
Ostrich and Seahorse
Examine the relationship between ratios and scale. Young math scholars compare ratios of two models. They use the ratios to make a comparison between the two models. Each image uses a different scale, which requires learners to think...
Noyce Foundation
Surrounded and Covered
What effect does changing the perimeter have on the area of a figure? The five problems in the resource explore this question at various grade levels. Elementary problems focus on the perimeter of rectangles and irregular figures with...
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...
EngageNY
How Do Dilations Map Lines, Rays, and Circles?
Applying a learned technique to a new type of problem is an important skill in mathematics. The lesson asks scholars to apply their understanding to analyze dilations of different figures. They make conjectures and conclusions to...
CK-12 Foundation
Area and Volume of Similar Solids: Similar Solids
Five questions make up an interactive designed to boosts knowledge of area and volume of solid figures. Question types include multiple-choice, true or false, and fill-in-the-blank. A scale model changes measurement to provide a visual...
Flipped Math
Unit 6 Review: Similar Figures
After a short review of the material from the Similar Figures Unit, pupils work through 18 problems to further practice the skills from the unit. Scholars apply those skills in the application problems at the end of the review.
EngageNY
How Do Dilations Map Angles?
The key to understanding is making connections. Scholars explore angle dilations using properties of parallel lines. At completion, pupils prove that angles of a dilation preserve their original measure.
EngageNY
Mid-Module Assessment Task: Grade 8 Module 3
How well does the class understand dilations? The three-part assessment presents problems related to the properties of dilations. Pupils perform dilations and determine whether a dilation is responsible for a specific image.
Illustrative Mathematics
Sand Under the Swing Set
Help the local elementary school fix their playground by calculating the amount of sand needed near the swing set. The problem practices setting up proportions and ratios with three different options for solving. You can chose the option...
Noyce Foundation
Which is Bigger?
To take the longest path, go around—or was that go over? Class members measure scale drawings of a cylindrical vase to find the height and diameter. They calculate the actual height and circumference and determine which is larger.
EngageNY
Modeling Using Similarity
How do you find the lengths of items that cannot be directly measured? The 13th installment in a series of 16 has pupils use the similarity content learned in an earlier resource to solve real-world problems. Class members determine...