This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Louis wants to give \$15 to help kids who need school supplies. He also wants to buy a pair of shoes for \$39. How much money will he have to save for ...

Students use this puzzle to practice 2-digit addition. There are two puzzles: one without regrouping and one with regrouping. These puzzles make a great math station/center as students are able to independently check their work. Students can also use this resource as a math choice for when they finished their work. 

This task/game allows students to practice addition while also thinking about ways to organize counting by randomly selecting two (two-digit) number cards and finding the sum. In addition, students are prompted with guiding questions to promote discourse. In closure, students use writing to reflect on their learning and thinking strategies during the game.

In this Flash game, students may use a variety of activities to practice counting, collecting, exchanging, and making change for coins. Coin representations may show their amounts or not; coins may also be represented by coin tiles on a 10x10 grid, to help visualize their values. The five activities are: count, in which students determine the value of a given set of coins; collect, in which students choose coins to represent a given value; exchange, in which students use the smallest number of coins to represent a given value; change from coins, in which students are given a set of coins and asked how much change would be for a dollar (essentially counting up); and change from value, in which students are given a price owed (from a dollar) and asked to make change. There is a "bank" at the lower left side of the applet in which coins may be exchanged for other coins of the same value.

According to Achieve the Core, (achievethecore.org), "The joint purpose of this task is to provide students an opportunity to practice two-digit subtraction with regrouping and to engage students in looking for and expressing regularity in repeated reasoning (MP.8). Throughout grade 2, students need many opportunities to practice subtraction in order to achieve fluency subtracting within 100 by the end of the grade. For students in grade 2, it is sufficient for them to recognize that differences of 9 will stem from numbers whose digits differ by 1, subtractions resulting in 18 will stem from numbers whose digits differ by 2, etc. "

Okta challenges you to a duel! That crazy octopus wants to play you in a game where the first person to choose cards with a specified sum wins. You can choose how many cards, what types of numbers, and Okta's level of strategy.

This activity was used as an addition to the lesson "NBT1 Ford and Logan Add 45 +36" https://www.illustrativemathematics.org/content-standards/tasks/2068. As a variation of the lesson I started with placing ten sticks and ones in a cup. I wrote the number of cubes in the cup on a piece of paper and set it on top of the cup. Along side the cup I placed more ten sticks and ones. "How many cubes are there altogether?" Together we counted the cubes, using tens and ones language (5 tens plus 2 tens equals 7 tens). After the students were confident in combining tens and ones, with regrouping, I moved onto the attached sheet. This helped move the students from a concrete model to a pictorial representation. It was very important that they used precise language when combining the tens and ones.

Module 1 sets the foundation for students to master the sums and differences to 20 and to  subsequently apply these skills to fluently add one-digit to two-digit numbers at least through 100 using place value understandings, properties of operations and the relationship between addition and subtraction.

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

In Module 4, students develop place value strategies to fluently add and subtract within 100; they represent and solve one- and two-step word problems of varying types within 100; and they develop conceptual understanding of addition and subtraction of multi-digit numbers within 200.  Using a concrete to pictorial to abstract approach, students use manipulatives and math drawings to develop an understanding of the composition and decomposition of units, and they relate these representations to the standard algorithm for addition and subtraction.

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

Module 7 presents an opportunity for students to practice addition and subtraction strategies within 100 and problem-solving skills as they learn to work with various types of units within the contexts of length, money, and data.  Students represent categorical and measurement data using picture graphs, bar graphs, and line plots.  They revisit measuring and estimating length from Module 2, though now using both metric and customary units.

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

This google slide show is for use with grade 2 students as a routine to build number sense. Strings of expressions are used to build connections and as a springboard for discussion. Each slide has a target addition strategy, though other strategies are encouraged as well.

This intereactive Flash applet helps children learn grouping, tally marks, place value, addition, and subtraction. Students help the alien spaceship move cows into corrals by counting by 5s and 10s. They also can apply those grouping skills to practice adding and subtracting two-digit numbers with regrouping. Audio cues and prompts reinforce the user's actions and facilitate counting and the development of math language.

What coins are in the bank? This 3 Act Task by Graham Fletcher begins with a short video. Coins are added to a bank that totals the value of the coins. Some of the coins and values are hidden as he adds them to the bank. First students make observations and estimates to begin determining which coins could be in the bank to total $1.00. Students then use images of the types of coins used and how many total coins are in the bank. Students are estimating, determining values of coins, problem solving, and adding, to determine coins in the bank.

The purpose of this task is to help students articulate their addition strategies and would be most appropriately used once students have a solid understanding of coin values.

(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.)

El módulo 1 establece la base para que los estudiantes dominen las sumas y diferencias a 20 y posteriormente apliquen estas habilidades para agregar con fluidez un dígito a los números de dos dígitos al menos a través de 100 utilizando entendimientos de valor de lugar, propiedades de las operaciones y la relación entre la adición y sustracción.

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

English Description:
Module 1 sets the foundation for students to master the sums and differences to 20 and to  subsequently apply these skills to fluently add one-digit to two-digit numbers at least through 100 using place value understandings, properties of operations and the relationship between addition and subtraction.

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

(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 el módulo 4, los estudiantes desarrollan estrategias de valor en el lugar para sumar y restar con fluidez dentro de los 100; Representan y resuelven problemas de palabras de una y dos pasos de tipos variables dentro de 100; y desarrollan la comprensión conceptual de la adición y la resta de los números de múltiples dígitos dentro de 200. Utilizando un enfoque concreto a pictórico a abstracto, los estudiantes usan manipulaciones y dibujos matemáticos para desarrollar una comprensión de la composición y descomposición de unidades, y relacionan estas representaciones con El algoritmo estándar para suma y resta.

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

English Description:
In Module 4, students develop place value strategies to fluently add and subtract within 100; they represent and solve one- and two-step word problems of varying types within 100; and they develop conceptual understanding of addition and subtraction of multi-digit numbers within 200.  Using a concrete to pictorial to abstract approach, students use manipulatives and math drawings to develop an understanding of the composition and decomposition of units, and they relate these representations to the standard algorithm for addition and subtraction.

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

(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.)

El módulo 7 presenta una oportunidad para que los estudiantes practiquen estrategias de adición y sustracción dentro de 100 y habilidades de resolución de problemas a medida que aprenden a trabajar con varios tipos de unidades dentro de los contextos de longitud, dinero y datos. Los estudiantes representan datos categóricos y de medición utilizando gráficos de imágenes, gráficos de barras y parcelas de línea. Revisan la medición y la longitud de estimación del módulo 2, aunque ahora utilizan unidades métricas y habituales.

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

English Description:
Module 7 presents an opportunity for students to practice addition and subtraction strategies within 100 and problem-solving skills as they learn to work with various types of units within the contexts of length, money, and data.  Students represent categorical and measurement data using picture graphs, bar graphs, and line plots.  They revisit measuring and estimating length from Module 2, though now using both metric and customary units.

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

In this challenging instructional task students relate addition and subtraction problems to money and to situations and goals related to saving money.