Students watch a dot get tossed from one number on a number line to the opposite of the number. Students predict where the dot will land each time based on its starting location.Key ConceptsThe opposite of a number is the same distance from 0 as the number itself, but on the other side of 0 on a number line.In the diagram, m is the opposite of n, and n is the opposite of m. The distance from m to 0 is d, and the distance from n to 0 is d; this distance to 0 is the same for both n and m. The absolute value of a number is its distance from 0 on a number line.Positive numbers are numbers that are greater than 0.Negative numbers are numbers that are less than 0.The opposite of a positive number is negative, and the opposite of a negative number is positive.Since the opposite of 0 is 0 (which is neither positive nor negative), then 0 = 0. The number 0 is the only number that is its own opposite.Whole numbers and the opposites of those numbers are all integers.Rational numbers are numbers that can be expressed as ab, where a and b are integers and b ≠ 0.Goals and Learning ObjectivesIdentify a number and its oppositeLocate the opposite of a number on a number lineDefine the opposite of a number, negative numbers, rational numbers, and integers

Four full-year digital course, built from the ground up and fully-aligned to the Common Core State Standards, for 7th grade Mathematics. Created using research-based approaches to teaching and learning, the Open Access Common Core Course for Mathematics is designed with student-centered learning in mind, including activities for students to develop valuable 21st century skills and academic mindset.

Working With Rational Numbers

Type of Unit: Concept

Prior Knowledge

Students should be able to:

Compare and order positive and negative numbers and place them on a number line.
Understand the concepts of opposites absolute value.

Lesson Flow

The unit begins with students using a balloon model to informally explore adding and subtracting integers. With the model, adding or removing heat represents adding or subtracting positive integers, and adding or removing weight represents adding or subtracting negative integers.

Students then move from the balloon model to a number line model for adding and subtracting integers, eventually extending the addition and subtraction rules from integers to all rational numbers. Number lines and multiplication patterns are used to find products of rational numbers. The relationship between multiplication and division is used to understand how to divide rational numbers. Properties of addition are briefly reviewed, then used to prove rules for addition, subtraction, multiplication, and division.

This unit includes problems with real-world contexts, formative assessment lessons, and Gallery problems.

Students use the Hot Air Balloon interactive to model integer addition. They then move to modeling addition on horizontal number lines. They look for patterns in their work and their answers to understand general addition methods.Key ConceptsTo add two numbers on a number line, start at 0. Move to the first addend. Then, move in the positive direction (up or right) to add a positive integer or in the negative direction (down or left) to add a negative integer.Here is −6 + 4 on a number line: The rule for integer addition (which extends to addition of rational numbers) is easiest to state if it is broken into two cases:If both addends have the same sign, add their absolute values and give the result the same sign as the addends. For example, to find −5 + (−9), first find |−5|  +|−9| = 14. Because both addends are negative the result is negative. So, −5 + (−9) = −14.If the addends have different signs, subtract the lesser absolute value from the greater absolute value. Give the answer the same sign as the addend with the greater absolute value. For example, to find 5 + (−9), find |−9| − |5| = 9 − 5 = 4. Because −9 has the greater absolute value, the result is negative. So, 5 + (−9) = −4.Goals and Learning ObjectivesModel integer addition on a number line.Learn general methods for adding integers.

Students use number lines to solve addition and subtraction problems involving positive and negative fractions and decimals. They then verify that the same rules they found for integers apply to fractions and decimals as well. Finally, they solve some real-world problems.Key ConceptsThe first four lessons of this unit focused on adding and subtracting integers. Using only integers made it easier for students to create models and visualize the addition and subtraction process. In this lesson, those concepts are extended to positive and negative fractions and decimals. Students will see that the number line model and rules work for these numbers as well.Note that rational number will be formally defined in Lesson 15.Goals and Learning ObjectivesExtend models and rules for adding and subtracting integers to positive and negative fractions and decimals.Solve real-world problems involving addition and subtraction of positive and negative fractions and decimals.

In this Cyberchase video segment, the CyberSquad helps resolve a dispute about the squares on the Gollywood Walk of Fame.

(Nota: Esta es una traducción de un recurso educativo abierto creado por el Departamento de Educación del Estado de Nueva York (NYSED) como parte del proyecto "EngageNY" en 2013. Aunque el recurso real fue traducido por personas, la siguiente descripción se tradujo del inglés original usando Google Translate para ayudar a los usuarios potenciales a decidir si se adapta a sus necesidades y puede contener errores gramaticales o lingüísticos. La descripción original en inglés también se proporciona a continuación.)

En este módulo de 35 días de grado 3, los estudiantes extienden y profundizan la práctica de segundo grado con "acciones iguales" para comprender las fracciones como particiones iguales de un todo. Su conocimiento se vuelve más formal a medida que trabajan con los modelos de área y la línea numérica.

Encuentre el resto de los recursos matemáticos de Engageny en https://archive.org/details/engageny-mathematics.

English Description:
In this 35-day Grade 3 module, students extend and deepen second grade practice with "equal shares" to understanding fractions as equal partitions of a whole. Their knowledge becomes more formal as they work with area models and the number line.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.

Numberstring.com describes number strings as "a set of related math problems, crafted to support students to construct big ideas about mathematics and build their own strategies."

This number string builds students understanding and strategies related to percent, particularly exploring questions such as, "3 is 25% of what number?"

SWBAT articulate strategies for determining a whole when given a part and the percentage it represents.

Whole numbers are no better than any others! Practice plotting values on the number line as a passionate activist rises up and demands equity for all numbers, including fractions and decimals.

Pearl Diver is a fun, interactive web-based game and app for iPad and iPhone. Players learn the number line while diving for pearls amidst shipwrecks and sunken ruins. This learning game addresses standard mathematic concepts included in the current Common Core curriculum such as:
-understanding numbers, ways of representing numbers, and number systems
-understanding and representing commonly used fractions
-understanding fractions as part of unit wholes and as locations on number lines
-comparing and ordering fractions, and finding their approximate locations on the number line
Pearl Diver is supported by supplementary materials including teacher’s guide, learner’s guide, “Teaching With Pearl Diver” video, and printable resources. It is available in English and Spanish. This game is available free on the Apple App Store.
This project was sponsored by NSF and developed by the Learning Games Lab in collaboration with researchers and mathematicians in the College of Education and College of Arts and Sciences at New Mexico State University.

Press Release Links:
http://newscenter.nmsu.edu/Articles/view/7833

Pearl Diver ACE award
http://newscenter.nmsu.edu/Articles/view/5230

Funding for Math Snacks (includes image of Pearl Diver)
http://newscenter.nmsu.edu/Articles/view/4828

Links to scholarly publications:

Trespalacios, J., & Chamberlin, B. (2012). Pearl Diver: Identifying numbers on a number line. Teaching Children’s Mathematics, 18, 446-447.

Navigate the number line while diving amidst shipwrecks and sunken ruins. Will you find a pearl, or an old boot? Watch out for the electric eel! Pearl Diver teaches properties of numbers, how to plot numbers, how to visualize quantity on the number line, how to order numbers, and how to use the number line as a visual model for mathematical operations.

In this video segment from Cyberchase, the CyberSquad learns how to read a thermometer as they try to keep their chocolate sculpture from melting.

Lesson OverviewStudents represent inequalities on a number line, find at least one value that makes the inequality true, and write the inequality using words.Example: x > 2The solutions to x ≤ a are represented on the number line with an arrow pointing to the left from a closed circle at a.Example: x ≤ 2The solutions to x ≥ a are represented on the number line with an arrow pointing to the right from a closed circle at a.Example: x ≥ 2Goals and Learning ObjectivesRepresent an inequality on a number line and using words.Understand that inequalities have infinitely many solutions.

The purpose of this task is for students to use the position of a number on the number line to round the number without knowing its exact value. Though this task deals most directly with rounding, it also requires students to understand or figure out that one tenth of 0.

Represent inequalities on a number line.
Represent inequalities using interval notation.
Use the addition and multiplication properties to solve algebraic inequalities and express their solutions graphically and with interval notation.
Solve inequalities that contain absolute values.
Combine properties of inequalities to isolate variables, solve algebraic inequalities, and express their solutions graphically.
Simplify and solve algebraic inequalities using the distributive property to clear parentheses and fractions.

(Nota: Esta es una traducción de un recurso educativo abierto creado por el Departamento de Educación del Estado de Nueva York (NYSED) como parte del proyecto "EngageNY" en 2013. Aunque el recurso real fue traducido por personas, la siguiente descripción se tradujo del inglés original usando Google Translate para ayudar a los usuarios potenciales a decidir si se adapta a sus necesidades y puede contener errores gramaticales o lingüísticos. La descripción original en inglés también se proporciona a continuación.)

En este módulo, los estudiantes reconectan y profundizan su comprensión de las estadísticas y los conceptos de probabilidad introducidos por primera vez en los grados 6, 7 y 8. Los estudiantes desarrollan un conjunto de herramientas para comprender e interpretar la variabilidad en los datos, y comienzan a tomar decisiones más informadas de los datos . Trabajan con distribuciones de datos de varias formas, centros y diferenciales. Los estudiantes se basan en su experiencia con datos cuantitativos bivariados del grado 8. Este módulo prepara el escenario para un trabajo más extenso con muestreo e inferencia en calificaciones posteriores.

Encuentre el resto de los recursos matemáticos de Engageny en https://archive.org/details/engageny-mathematics.

English Description:
In this module, students reconnect with and deepen their understanding of statistics and probability concepts first introduced in Grades 6, 7, and 8. Students develop a set of tools for understanding and interpreting variability in data, and begin to make more informed decisions from data. They work with data distributions of various shapes, centers, and spreads. Students build on their experience with bivariate quantitative data from Grade 8. This module sets the stage for more extensive work with sampling and inference in later grades.

Find the rest of the EngageNY Mathematics resources at https://archive.org/details/engageny-mathematics.