In this activity, students explore the effect of chemical erosion on statues and monuments. They use chalk to see what happens when limestone is placed in liquids with different pH values. They also learn several things that engineers are doing to reduce the effects of acid rain.

Students are introduced to the differences between acids and bases and how to use indicators, such as pH paper and red cabbage juice, to distinguish between them.

Students will learn to identify and define acid and base and classify household chemicals as acids or bases using universal iindicator.

In this video, a student explains how to use the area model for multiplication. The area model is a multiplication strategy based on decomposing numbers basedon place value.

An interactive applet and associated web page that explain the area of a triangle. The applet shows a triangle that can be reshaped by dragging any vertex. As it changes, the area is continually recalculated using the 'half base times height' method. The triangle has a fixed square grid in its interior that can be used to visually estimate the area for later correlation with the calculated value. The calculation can be hidden while estimation is in progress. The text page has links to a similar page that uses Heron's Formula to compute the area. 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.

Part of NCSSM CORE collection: This is the document for a buffer activity lab. Students will measure and record the pH of various solutions and then measure the pH of the solution after the addition of a buffer solution. They will use their results to gauge the effectiveness of the buffers. NOTE: This lab uses CBL probes and TI-83+ calculators.

This resource is from Tools4NCTeachers. This file contains a set of 2 tasks (including scoring rubric and student recording sheet).  The tasks may be used for instruction or assessment. Remix this resource to include student work samples or addtional tasks.

This resource is from Tools4NCTeachers.In this lesson, students develop an understanding of place value by using arrow cards.  The focus of this lesson is on writing numbers using expanded form.Arrow cards are place value cards with an "arrow" or point on the right side.  Students can organize the cards to represent numbers in expanded notation. OR, they can overlap cards and (lining up the arrows) to form multi-digit numbers. Printable arrow cards are provided with this resource.. 

This resource is from Tools4NCTeachers.A Common Formative Assessment (CFA) provides a snapshot of current student understanding. It serves as a checkpoint, and may be used to guide future whole and small group instruction. This CFA addresses 2nd grade, Cluster 4 standards.

This resource is from Tools4NCTeachers.Math games are fun, motivating, and provide opportunities for students to build number concepts, reasoning, and fluency. These games may be used as math stations or as whole group learning opportunities. This file contains directions and materials for Cluster 5 math games.

This resource is part of Tools4NCTeachers.

The goal of this lesson is for students to understand that plane figures are different from solid figures. Students will identify and locate the face of a solid figure that matches a plane figure, such as the face of a cube is a square, the base of a triangular based pyramid is a triangle.

This resource is part of Tools4NCTeachers.

In this task, students count on from a given number, and analyze the place value of the digits within numbers. The task may be used for instructional or assessment purposes.

This resource is part of Tools4NCTeachers.

In this task, students group sets of counters into tens and leftover ones. The task may be used for instructional or assessment purposes.

This resource is part of Tools4NCTeachers.

In this lesson students use the open number and various strategies to solve two-step story problems.

This resource is part of Tools4NCTeachers.

In this lesson, students compare two-digit numbers based on the meanings of the tens and ones digits.

This resource is from Tools4NCTeachers.Students need distributed practice of newly-learned skills to develop fluency, build proficiency, and deepen understanding. This file contains directions for activities which may be used as Cluster 4 games or math stations.

This resource is part of Tools4NCTeachers.

In this lesson, students will compare and reason about the values of two-digit numbers based on the number of tens and ones in the numbers.

This resource is part of Tools4NCTeachers.

In this task, students count a set of cubes, record the matching numeral, and determine which digit is in the ones place and which is in the tens place. The task may be used for instructional or assessment purposes.

This resource is part of Tools4NCTeachers.

In this task, students apply their place value understanding to compose and decompose 2-digit numbers. A scoring rubric is included. The task may be used for instructional or assessment purposes.

This resource is from Tools4NCTeachers.In this lesson, small groups of students play a game where they spin 3-digit numbers, build them using arrow cards, and compare the numbers.  Several extension activities and math centers are shared in this lesson.