Blast a Buick out of a cannon! Learn about projectile motion by firing various objects. Set the angle, initial speed, and mass. Add air resistance. Make a game out of this simulation by trying to hit a target.

This problem gives practice in calculating with percentages. It can be approached by trial and improvement but the equivalence between fractions and percentages is very useful.

This lesson focuses on students making decisions about what tools to apply to solve different problems related to quadratic expressions and equations. It is also intended to build awareness of the form an answer will take in order to help students make sense of the kind of problem they are solving. (9th/10th/11th Grade Math)

This question provides students with an opportunity to see expressions as constructed out of a sequence of operations: first taking the square root of n, then dividing the result of that operation into s. Students studying statistics encounter the expression in this question as the standard deviation of a sampling distribution with samples of size n when the distribution from which the sample is taken has standard deviation s.

This task has some aspects of a mathematical modeling problem (SMP 4) and it also illustrates SMP 1 (Making sense of a problem). Students are given all the relevant information on the nutritional labels, but they have to figure out how to use this information. They have to come up with the idea that they can set up two equations in two unknowns to solve the problem.

This tasks is an example of a mathematical modeling problem (SMP 4) and it also illustrates SMP 1 (Making sense of a problem). Students are only told that there are two ingredients in the pasta and they have a picture of the box. It might even be better to just show the picture of the box, or to bring in the box and ask the students to pose the question themselves.

The purpose of the task is to show students a situation where squaring both sides of an equation can result in an equation with more solutions than the original one. The reason for this is that it is possible to have two unequal numbers whose squares are equal.

Explore forces, energy and work as you push household objects up and down a ramp. Lower and raise the ramp to see how the angle of inclination affects the parallel forces acting on the file cabinet. Graphs show forces, energy and work.

This problem would be a good one when doing calculations with fractions. It also requires logical thinking and organizing of results. Different strategies and approaches can be taken: knowledge of addition, or multiples, or an understanding of fractions can be used to arrive at a solution.

This lesson unit is intended to help teachers assess how well students are able to: translate between decimal and fraction notation, particularly when the decimals are repeating; create and solve simple linear equations to find the fractional equivalent of a repeating decimal; and understand the effect of multiplying a decimal by a power of 10.

This Nrich problem offers carefully chosen examples intended to give students the opportunity to prove that any recurring decimal can be written as a fraction. Together with the problems Terminating or Not and Tiny Nines, this problem offers valuable insights into the relationship between fractional and decimal representations.

Learn about the physics of resistance in a wire. Change its resistivity, length, and area to see how they affect the wire's resistance. The sizes of the symbols in the equation change along with the diagram of a wire.

This problem confronts students with the idea that when collecting data to try to answer a question it is important to identify all the relevant variables, and that an over-simplistic analysis with a limited amount of information can lead to the wrong decisions.

The problem also offers the opportunity for students to practice calculating ratios, percentages and proportions.

This Nrich problem appears at first to be about angles and rotations, but as students explore more deeply, they may be surprised to discover links to factors, multiples and primes. The images and interactivity provide an enticing hook to stimulate students' curiosity.

Students use a variety of properties concerning circles and sectors to justify statements.

This Nrich activity provides a meaningful task for practicing rounding two-digit numbers to the nearest multiple of 10. It encourages children to record their results, notice patterns and make predictions.

In this NRich activity students will analyze a pattern on a coordinate plane in order to make predictions.

This Nrich problem lets you spot misconceptions your students have about subtraction and division of fractions, while giving students an opportunity to practice the procedures in an intriguing context - students' curiosity will be raised by the strange patterns in the calculations, and we hope they will yearn to explain what is happening.

This Nrich problem is a good opportunity to encourage children to have a system for finding all possible solutions. It is also an ideal context in which to help children deepen their understanding of factors and multiples in a playful environment.

This Nrich activity will be very useful when wishing to challenge and extend pupils' spatial awareness with 2D shapes. It can also be an exercise in perseverance.