Open Middle provides math problems that have a closed beginning, a closed end, and an open middle. This means that there are multiple ways to approach and ultimately solve the problems. Open middle problems generally require a higher Depth of Knowledge than most problems that assess procedural and conceptual understanding.

This problem provides students practice in fractions (tenths) and challenges students' addition and subtraction skills. Students are given a cake with the numbers zero to nine on it. They are asked to cut the cake into three pieces with three cuts so that the numbers on each piece add to the same total. The Teachers' Notes page offers rationale, discussion questions, ideas for extension and support, and a printable (pdf) worksheet of the problem.

In this lesson, students will review decimal division as we prepare for our end of unit test. This will include dividing whole numbers by decimals, decimals by decimals, and decimals by whole numbers.

This task requires students to recognize both "number of groups unknown" and "group size unknown" division problems in the context of a whole number divided by a unit fraction.

The focus of the Division with Arrays intervention is using arrays to solve division problems with a known number of rows or a known number of objects in each row.

The purpose of this task is to introduce the idea of exponential growth and then connect that growth to expressions involving exponents. It illustrates well how fast exponential expressions grow.

This infographic dissects some reading instructional practices to highlight whether or not they are aligned with the science of reading and determine if they have the green light to use with all learners. This infographic will help teachers build a repertoire of direct and systematic instructional practices that will allow our students to access text effectively and efficiently.

This problem allows the student to think geometrically about lines and then relate this geometry to linear functions. Or the student can work algebraically with equations in order to find the explicit equation of the line through two points (when that line is not vertical).

This task is designed as a follow-up to the task F-LE Do Two Points Always Determine a Linear Function? Linear equations and linear functions are closely related, and there advantages and disadvantages to viewing a given problem through each of these points of view. This task is intended to show the depth of the standard F-LE.2 and its relationship to other important concepts of the middle school and high school curriculum, including ratio, algebra, and geometry.

This problem complements the problem ``Do two points always determine a linear function?''

Often described as a living document, the Constitution is constantly being interpreted and reinterpreted by the U.S. Supreme Court, federal appeals courts, and Congress in order to address the ever-changing needs and demands of the people. While many argue that "We the People of the United States" refers only to legal citizens, the Supreme Court and lawmakers have consistently disagreed, and for longer than you may think.

This task requires students to use the normal distribution as a model for a data distribution. Students must use given means and standard deviations to approximate population percentages. There are several ways (tables, graphing calculators, or statistical software) that students might calculate the required normal percentages. Depending on the method used, answers might vary somewhat from those shown in the solution.

This task requires students to use the normal distribution as a model for a data distribution. Students must use given means and standard deviations to approximate population percentages.

An overview of how the Dewey system is designed. The types of content found in the ten categories. Followed by an assessment quiz-game.

This game for two or more players tests students' knowledge of the uses of various measuring tools. An interactive spinner picturing 8 tools that measure the attributes of length, weight, volume, angle and time determines the players' movement on a game board. Students must explain their reasoning about their choices of tool applications. A printable page is available.

Do you ever use online reviews to help you make decisions about movies, books, stores or music? How do you know they aren’t fake?

The purpose of the task is to analyze a plausible real-life scenario using a geometric model

The purpose of the task is to analyze a plausible real-life scenario using a geometric model. The task requires knowledge of volume formulas for cylinders and cones, some geometric reasoning involving similar triangles, and pays attention to reasonable approximations and maintaining reasonable levels of accuracy throughout.