This task requires interpreting a function in a non-standard context. While the domain and range of this function are both numbers, the way in which the function is determined is not via a formula but by a (pre-determined) sequence of coin flips. In addition, the task provides an opportunity to compute some probabilities in a discrete situation.

The task is better suited for instruction than for assessment as it provides students with a non standard setting in which to interpret the meaning of functions. Students should carry out the process of flipping a coin and modeling this Random Walk in order to develop a sense of the process before analyzing it mathematically.

This task provides a context to calculate discrete probabilities and represent them on a bar graph. It could also be used to create a class activity where students gather, represent, and analyze data, running simulations of the random walk and recording and then displaying their results.

This task completes the line of reasoning of Random Walk III in a situation where the numbers become too large to calculate and so abstract reasoning is required in order to compare the different probabilities. It is intended for instructional purposes only with a goal of understanding how to calculate and compare the combinatorial symbols.

This task makes for a good follow-up task on rational irrational numbers after that the students have been acquainted with some of the more basic properties. In addition to eliciting several different types of reasoning, the task requires students to rewrite radical expressions in which the radicand is divisible by a perfect square (N-RN.2).

In some textbooks, a distinction is made between a ratio, which is assumed to have a common unit for both quantities, and a rate, which is defined to be a quotient of two quantities with different units (e.g. a ratio of the number of miles to the number of hours). No such distinction is made in the common core and hence, the two quantities in a ratio may or may not have a common unit. However, when there is a common unit, as in this problem, it is possible to add the two quantities and then find the ratio of each quantity with respect to the whole (often described as a part-whole relationship).

Students investigate the endothermic reaction involving citric acid, sodium bicarbonate and water to produce carbon dioxide, water and sodium citrate. In the presence of water [H2O], citric acid [C6H8O7] and sodium bicarbonate [NaHCO3] (also known as baking soda) react to form sodium citrate [Na3C6H5O7], water [H2O], and carbon dioxide [CO2]. Students test a stoichiometric version of the reaction followed by testing various perturbations on the stoichiometric version in which each reactant (citric acid, sodium bicarbonate, and water) is strategically doubled or halved to create a matrix of the effect on the reaction. By analyzing the test matrix data, they determine the optimum quantities to use in their own production companies to minimize material cost and maximize CO2 production. They use their test data to "scale-up" the system from a quart-sized ziplock bag to a reaction tank equal to the volume of their classroom. They collect data on reaction temperature and CO2 production.

In this brief, Christine Patton and Justina Wang, from Harvard Family Research Project, look at ways of helping to make the transition into kindergarten a positive experience that will serve as a foundation to help children reach their full potential throughout their school years. The brief highlights promising practices in six states—New Jersey, Georgia, Maryland, Minnesota, Virginia, and California—where local- and state-level leadership support a variety of initiatives to ensure successful transitions into kindergarten. The authors examine effective collaborative approaches in which state departments of education, advocacy organizations, school districts, early education teachers, kindergarten teachers, families, and community members work together to help kindergartners enter school ready to begin this pivotal new phase of their lives

Students observe an in-classroom visual representation of a volcanic eruption. The water-powered volcano demonstration is made in advance, using sand, hoses and a waterballoon, representing the main components of all volcanoes. During the activity, students observe, measure and sketch the volcano, seeing how its behavior provides engineers with indicators used to predict an eruption.

This task helps students understand that when you multiply by a number you always get a bigger number.

The three tasks in this set are not examples of tasks asking students to compute using the standard algorithms for multiplication and division because most people know what those kinds of problems look like. Instead, these tasks show what kinds of reasoning and estimation strategies students need to develop in order to support their algorithmic computations.

The three tasks (including part 1 and part 3) in this set are not examples of tasks asking students to compute using the standard algorithms for multiplication and division because most people know what those kinds of problems look like. Instead, these tasks show what kinds of reasoning and estimation strategies students need to develop in order to support their algorithmic computations.

"Rebecca Burgess sees a problem with the way many people perceive the autism spectrum. Her resolution? The comic below. The Tumblr user debuted “Understanding the Spectrum” (below), which gets rid of the linear autism spectrum image (i.e. you’re either “not autistic, “very autistic” or somewhere in between) and replaces it with a round spectrum full of several traits or ways the brain processes information."

Why do we care about air? Breathe in, breathe out, breathe in... most, if not all, humans do this automatically. Do we really know what is in the air we breathe? In this activity, students use M&M(TM) candies to create pie graphs that show their understanding of the composition of air. They discuss why knowing this information is important to engineers and how engineers use this information to improve technology to better care for our planet.

This tasks gives a verbal description for computing the perimeter of a rectangle and asks the students to find an expression for this perimeter. Students then have to use the expression to evaluate the perimeter for specific values of the two variables.

This task is a natural follow up for task Rectangle Perimeter 1. After thinking about and using one specific expression for the perimeter of a rectangle, students now extend their thinking to equivalent expressions for the same quantity.

The purpose of this task is to ask students to write expressions and to consider what it means for two expressions to be equivalent.

This task is written so that students have opportunities to use different strategies to determine whether a set has an even or odd number of objects.

This task is a reasonably straight-forward application of rigid motion geometry, with emphasis on ruler and straightedge constructions, and would be suitable for assessment purposes.

The goal of this task is to give students an opportunity to experiment with reflections of triangles on a coordinate grid. Students are not prompted in the question to list the coordinates of the different triangle vertices but this is a natural extension of the task.