Illustrative Mathematics
Ratio of Boys to Girls
How many boys are in the class? Here is an introductory exercise describing ratios. The commentary shows different ways learners can approach the problem, using a tape diagram of boys to girls and using a table. The activity includes...
EngageNY
Ratios and Unit Rates
This turn-key unit on ratios and unit rates walks through a 30-lesson unit on teaching proportional reasoning, with each lesson broken into detailed teaching notes and time allotments for all parts. An unbelievable resource when taken...
Illustrative Mathematics
Voting for Three, Variation 2
Here is another opportunity for math students to apply reasoning to solve real-world problems with ratios. The ratio of the number of votes for two candidates is provided. Your class is asked to use this ratio and information given about...
Illustrative Mathematics
Jim and Jesse's Money
Jim and Jesse started their road trip with the same amount of money. Your class must find the amount of money each one had given, the amount of money spent, and the ratio of money at the end. This is a comprehensive problem that...
Illustrative Mathematics
Running at a Constant Speed
The learner must use the given constant speed to find the unit rate. A table is made in order to relate the speed to the time and the distance. From the table, learners are able to see the unit rate in miles per minute and miles per...
EngageNY
More About Similar Triangles
Determine whether two triangles are similar. The instructional activity presents opportunities for pupils to find the criterion needed to show that two triangles are similar. Scholars use the definition of similarity to find any missing...
Scholastic
Study Jams! Rate
Zoe is reading books over vacation and wants to know at her current rate, how many will she finish by the end. Building on prior knowledge of fractions and ratios, young mathematicians learn how equivalent rates are used to answer her...
EngageNY
Comparing the Ratio Method with the Parallel Method
Can you prove it? Lead your class through the development of the Side Splitter Theorem through proofs. Individuals connect the ratio and parallel method of dilation through an exploration of two proofs. After completing the proofs,...
EngageNY
Dividing Segments Proportionately
Fractions, ratios, and proportions: what do they have to do with segments? Scholars discover the midpoint formula through coordinate geometry. Next, they expand on the formula to apply it to dividing the segment into different...
Curated OER
Sore Throats, Variation 1
Why does Nia's water taste saltier than Trey's if she put more into her cup than he did? Math masters set up proportions in order to compare the mixtures. This task effectively has learners apply the concepts of ratio and proportion to a...
EngageNY
Trigonometry and the Pythagorean Theorem
Ancient Egyptians sure knew their trigonometry! Pupils learn how the pyramid architects applied right triangle trigonometry. When comparing the Pythagorean theorem to the trigonometric ratios, they learn an important connection that...
EngageNY
The Definition of Sine, Cosine, and Tangent
Introduce your classes to a new world of mathematics. Pupils learn to call trigonometric ratios by their given names: sine, cosine, and tangent. They find ratios and use known ratios to discover missing sides of similar...
EngageNY
What Is a Trigonometric Identity?
Protect yourself from identity theft! Establishing a strong understanding of the Pythagorean identity allows learners to prove that sine^2x + cos^2x = 1. They then use the identity to find sine or cosine ratios given the other.
Curated OER
Dragonfly
The speed of a dragonfly brings math into the real world as your learners collaboratively see the value in calculating unit rates in direct proportion problems. This six-phase lesson encourages you, as the teacher, to only ask questions...
National Research Center for Career and Technical Education
Photoshop Scale
Say cheese! Can your class take a great photo and size it to fit any need? A career and technology-centered lesson plan demonstrates the correct way to resize images in Adobe Photoshop. Scholars view a presentation and work individually...
02 x 02 Worksheets
Proportions
Cut-and-paste a great activity into your lesson plans. Scholars analyze real-world problems involving proportions. To change things up a bit they cut-and-paste quantities to create a proportion on their way to solving the problems.