Curated OER
Rounding and Subtracting
Common Core is all about getting your learners to open their minds and think about the why and how. This problem has them thinking about unknown numbers and their relationship with one another when we round and...
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.
Census at School
Just How Old Are You?
Do you know how old you are in seconds, minutes, days, weeks, or months? This intriguing question is presented as a way for learners to estimate in units of time. They'll build a better sense of what each increment of time is as they...
Illustrative Mathematics
How Many Leaves on a Tree?
This is great go-to activity for those spring or fall days when the weather beckons your geometry class outside. Learners start with a small tree, devising strategies to accurately estimate the leaf count. They must then tackle the...
International Technology Education Association
Sizing Up the Clouds
How much rain can that cloud make? Through a simulation, the class estimates the amount of candy rain contained in different cup clouds. After probing the clouds using different methods, class members adjust their estimates. Participants...
Illustrative Mathematics
How Thick Is a Soda Can I?
The humble soda can gets the geometric treatment in an activity that links math and science calculations. After a few basic assumptions are made and discussed, surface area calculations combine with density information to develop an...
Illustrative Mathematics
Estimating Square Roots
No calculators! Assure your learners that they can find the square root of a large number. All they need are two known squares close by and a table. Come up with an additional practice and your number crunchers will have it mastered in...
David Pleacher
Candy Math Fun
Few things can motivate children to learn like the promise of a sweet and tasty treat. Given a bag of M&M®s, Skittles®, or other colorful candy, students first predict the contents of the bag before counting the pieces,...
Teach Engineering
Cost Comparisons
Our final proposal for the cost of the bridge requested is ... In the last segment in a series of 10, pairs work together to develop a proposal for a city bridge design. The class completes a cost comparison between concrete and steel to...
Illustrative Mathematics
Tax and Tip
Finding out how to calculate tax and tip is a valuable skill that all young adults should be able to do without a calculator. Learners are given a bill and asked to calculate the tax, tip, and total amount. Calculations can be exact or...
Illustrative Mathematics
Eratosthenes and the Circumference of the Earth
The class gets to practice being a mathematician in ancient Greece, performing geometric application problems in the way of Eratosthenes. After following the steps of the great mathematicians, they then compare the (surprisingly...
Curated OER
Jelly Beans for Sale
Students connect literature (story Jelly Beans for Sale by Bruce McMillan) to math concepts. In these estimating and money lessons, students work with jelly beans, unifix cubes, pennies, nickels, dimes, and quarters, to estimate and make...
Illustrative Mathematics
High School Graduation
An exercise in finding the approximate time that a name would be called at a graduation. Estimating time may be difficult for some of the class, so this resource would not be a good choice for learning this standard. It does end with a...
Curated OER
Valentine Marbles
if you've ever had to guess how many items were in a jar, then this problem is for you! With a big jar full of red and white marbles, does picking a sample of 16 allow your learners to get a good estimate on the percentages of each...
Teach Engineering
About Accuracy and Approximation
How accurate are robots? Groups draw lines by moving robots backwards and forwards by one rotation of the wheels. Using the appropriate formula, they determine the percent error in the length of the lines in relation to the calculated...
Illustrative Mathematics
Why Randomize?
Your statisticians draw several samplings from the same data set, some randomized and some not, and consider the distribution of the sample means of the two different types of samplings. The exercise demonstrates that non-random samples...
Yummy Math
Soda Santa
Santa is the focal point of a worksheet that inquires how many cans and boxes of soda were used to create a supermarket display. As a small group project, the discussions that will ensue to evaluate the task's three questions will...
AAA Math
Aaa Math: Estimating a Sum by Rounding
Use rounding to estimate the answer to an addition problem in this online game. As you play the game, running totals of correct and incorrect answers and your score are displayed.
Texas Instruments
Texas Instruments: Estimating With Rational Numbers
In this activity, students will round fractions and mixed numbers, and then use their rounding skills to estimate sums, differences, products, and quotients.
University of Georgia
University of Georgia: Texas Area Estimate
Drawings and discussion of several methods to estimate the area of an irregular shape, like the state of Texas.
Shmoop University
Shmoop: Ratios & Percentages: Estimating Percentages
The mathematics tutorial examines how to estimate percentages using shortcuts. Students learn about the concept through notes, examples, and practice problems.
Hunkins Experiments
Hunkin's Experiments:how to Measure the Height of a Tree
Hunkin's Experiments is a group of simple cartoon illustrations of scientific principles. Some would work well in the classroom, but others have little value beyond entertaining students. All of the projects are easy to do. This part...
Shodor Education Foundation
Shodor Interactivate: Comparison Estimator
Use this applet to practice your estimating skills comparing length, area, counting or a random sampling of those topics. You can also adjust the difficulty and the precision needed. The applet also lets you know how close you are to the...
NumberNut
Number Nut: Estimate and Round Why Is This Important?
Problem solving will become a little easier when you understand the concepts of estimation and rounding. Explore how these concepts are used in mathematics and real world applications. Detailed examples and links to related games...