A web page and interactive applet show how to compute the perimeter of a triangle. A triangle is shown that can be resized by dragging its vertices. As you drag, the perimeter is continuously recalculated. Text on the page explains that the perimeter is the sum of the sides. For those who prefer it, in a formula that is given. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference interactive geometry reference book project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the concept of 'perpendicular'. The applet presents two intersecting line segments, one initially at right angles to the other. As you drag the end points of the line segments a message and the right-angle mark at the intersection tell if it is currently perpendicular. The goal is to show what a right angle 'looks like'. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the perpendicular bisector of a line segment. The applet shows a fixed line and another moveable one that bisects it. As you drag either end of it, it is seen that only when they are perpendicular to each other is the definition valid. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that show how to determine of one line is perpendicular to another in coordinate geometry. The principle used is that if two lines a re perpendicular to each other the slope of one is the negative reciprocal of the other. The applet shows to lines that the user can move. The slopes are continuously calculated as you drag them, and if the they are parallel they change color. The calculation is shown on screen updated continuously as you drag. The grid, axis pointers and coordinates can be turned on and off. The calculation display can be turned off to permit class exercises and then turned back on the verify the answers. The applet can be printed as it appears on the screen to make handouts. The web page has a full description of the concept of perpendicularity, a worked example and has links to other pages relating to coordinate geometry. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Pet Bingo is a whimsical mathematical world for everyone! Come watch your child’s understanding of addition, subtraction, multiplication and division grow with their very own pets! Feed your pets and your child’s minds!

Pet Bingo features the following K-4 math skills:
ADDITION & SUBTRACTION:
– Add and subtract up to 10, 20, 100, 1000 and more
– Add up to four digit numbers
– Add and subtract multi-digit whole numbers
MULTIPLICATION & DIVISION:
– Practice times tables 1 to 12
– Multiply and divide by 100
– Multiply whole numbers by 10
MEASUREMENT/GEOMETRY:
– Represent whole numbers on an equally spaced numberline
– Understand concepts of area and relation to multiplication and addition

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Students - make sure you have your parents permission.

We're going to finish up our discussion of p-values by taking a closer look at how they can get it wrong, and what we can do to minimize those errors. We'll discuss Type 1 (when we think we've detected an effect, but there actually isn't one) and Type 2 (when there was an effect we didn't see) errors and introduce statistical power - which tells us the chance of detecting an effect if there is one.

Today we’re going to finish up our unit on data visualization by taking a closer look at how dot plots, box plots, and stem and leaf plots represent data. We’ll also talk about the rules we can use to identify outliers and apply our new data viz skills by taking a closer look at how Justin Timberlake’s song lyrics have changed since he went solo.

This year my major plan for integrating critical thinking and collaboration included a major classroom change. I was rearranged my classroom into pods and I started presenting my lessons in a flipped form.
The pods and flipped classroom provided an opportunity for critical thinking and collaboration. The students were to watch the videos and write down any questions they had on the material. They then met up as a group to go over the material. I found the students would have impressive conversations on the material. They then also worked in their pods to complete the daily practice. I found it was great for the students to be able to work together through problems and struggles. I was constantly happy to hear the students offer their own explanations to each other.

An interactive applet and associated web page that demonstrate polygons. The applet shows a polygon which is initially an irregular convex pentagon. The user can drag any vertex and a message shows if it becomes concave. The user can also alter the number of sides from 3 to 99, the title changing to reflect it's name up to 12 sides. You can also make it regular, dragging a vertex then changes all vertices to maintain it as regular. The web page has many definitions and links to the various forms and orders of polygon. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate that the exterior angles of a polygon always add to a constant (360 or 720 depending on your point of view). The applet shows a polygon where the user can drag the vertices to reshape it, alter the number of sides, make it convex or concave, regular or irregular. The applet shows the angle summation in real time, demonstrating that it is always constant. It also demonstrates how exterior angles are accounted for in concave polygons, where the exterior angle seems to be inside the figure. These are taken as negative angles and the sum demonstrably remains the same. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate that the interior angles of a polygon always add to a number related only to the number of sides. The applet shows a polygon where the user can drag the vertices to reshape it, alter the number of sides, make it convex or concave, regular or irregular. The applet shows the angle summation in real time, demonstrating that only the number of sides affects the total. The text on the web page gives the formula for the total of the interior angles. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

An interactive applet and associated web page that demonstrate the diagonals of a polygon. The applet shows a polygon with the diagonals drawn. The user can drag any vertex, make it regular or irregular, and change the number of sides. The applet continually computes and displays the number of diagonals. The text on the web page has the relevant formulae. Applet can be enlarged to full screen size for use with a classroom projector. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Preschool is the perfect time to make math fun and relevant for kids. These engaging worksheets teach ordering skills, matching, counting, and number lines, which are the basis for future math success. Create dynamic, custom preschool activity books based on your students' level and abilities that will help them believe in this equation: Math = Excitement!

This comprehension resource from edHelper offers loads of preschool math lessons, activities, and worksheets in lots of areas: math review booklets, mazes, matching, shapes, ordering, counting, grids, greater than/less than, shapes, book units, number lines, comparing numbers, and skip counting.

A page that allows you to print rectangular (cartesian) graph paper. You ca control if grid lines are printed and the position of the origin. By dargging the origin into any corner a single quadrant can be printed. This resource is a component of the Math Open Reference Interactive Geometry textbook project at http://www.mathopenref.com.

Today we’re going to begin our discussion of probability. We’ll talk about how the addition (OR) rule, the multiplication (AND) rule, and conditional probabilities help us figure out the likelihood of sequences of events happening - from optimizing your chances of having a great night out with friends to seeing Cole Sprouse at IHop!

Today we're going to introduce bayesian statistics and discuss how this new approach to statistics has revolutionized the field from artificial intelligence and clinical trials to how your computer filters spam! We'll also discuss the Law of Large Numbers and how we can use simulations to help us better understand the "rules" of our data, even if we don't know the equations that define those rules.