Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
The purpose of this How Many Do You See? is for students to subitize or use grouping strategies to describe the images they see. Students see two-color counters on the 10-frame and may know that when the 10-frame is filled, it shows 10. Then students may see how many squares of the frame are not filled and subtract that many from 10, or they may see how many squares are filled in each row and add those together. This deepens students’ understanding of the structure of 10 (MP7).
Launch
Groups of 2
“¿Cuántos ven? ¿Cómo lo saben?, ¿qué ven?” // “How many do you see? How do you see them?”
Flash the first image.
30 seconds: quiet think time
Activity
Display the image.
“Discutan con su pareja lo que pensaron” // “Discuss your thinking with your partner.”
1 minute: partner discussion
Record responses.
Repeat for each image.
Student Task Statement
¿Cuántos ves?
¿Cómo lo sabes?, ¿qué ves?
Student Response
Activity Synthesis
“¿Cómo les ayuda la estructura del tablero de 10 a ‘ver’ el total?” // “How does the structure of the 10-frame help you ‘see’ the total?” (I know that when the 10-frame is filled it shows 10. I can see how many squares are not filled and subtract that many from 10, or I can see how many squares are filled in each row and add those together.)
The purpose of this activity is for students to sort addition expressions by their value. Students find the value of each sum on their own and share their method with a partner, moving students towards fluency. This sorting task gives students opportunities to analyze equivalent expressions closely and make connections (MP2, MP7).
During the Synthesis, the teacher introduces an equation with addition expressions on both sides of the equal sign.
MLR8 Discussion Supports. Synthesis: Before students share, remind students to use “suma” // “sum” and “expresión” // “expression.” Advances: Speaking, Conversing
The purpose of this activity is for students to determine whether equations are true or false. Students may use a combination of computation and reasoning about the commutative property to determine whether each equation is true or false. The Synthesis focuses on how students can use the structure of the expressions to decide whether they are true or false, without finding the value of both sums (MP7).
Representation: Internalize Comprehension. Provide students with a graphic organizer, such as a two-column table or sorting mat, to visually represent the expressions on each side of the equations. Supports accessibility for: Visual Spatial Processing, Conceptual Processing
Launch
Groups of 4
Give students access to connecting cubes or two-color counters.
“Acabamos de encontrar expresiones que eran iguales. Miren esta ecuación” // “We just found expressions that were equal to each other. Look at this equation.”
Display .
“¿Esta ecuación es verdadera o falsa? ¿Cómo lo saben?” // “Is this equation true or false? How do you know?” (False, because , but the other side of the equal sign is 1 more than 6.)
30 seconds: quiet think time
1 minute: partner discussion
Share responses.
Lesson Synthesis
Display .
“Hoy trabajamos con ecuaciones que tienen expresiones en ambos lados del signo igual. ¿Qué le responderían a una persona si les dice que esta ecuación es verdadera porque ?” // “Today we worked with equations that have expressions on both sides of the equal sign. What would you tell someone who said this equation was true because ?” (This side of the equal sign is 8 and the other side is 9. 8 does not equal 9.)
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Give each group 1 set of addition expression cards. Or 1 student in each group can retrieve their cards from a previous lesson.
“Hoy vamos a clasificar las tarjetas en grupos de tarjetas que tengan el mismo valor” // “Today we are going to sort the cards into groups with the same value.”
Display an addition expression card, such as .
“Yo sé que el valor de esta suma es 7. Es una suma que ya me sé. Primero, voy a hacer un montón con las sumas de 7” // “I know the value of this sum is 7. It is a sum that I just know. I will start a pile for sums of 7.”
Activity
“Este grupo de tarjetas muestra expresiones de suma. Clasifiquen las tarjetas en grupos de tarjetas que tengan el mismo valor. Con su compañero, expliquen por qué las tarjetas van juntas. Asegúrense de que cada uno tenga la oportunidad de encontrar el valor antes de poner la tarjeta en un grupo. Si están en desacuerdo, trabajen juntos para encontrar el valor de la suma” // “This set of cards show addition expressions. Sort the cards into groups with the same value. Work with your partner to explain why the cards go together. Make sure that each partner has a chance to find the value before you place the card in a group. If you and your partner disagree, work together to find the value of the sum.”
12 minutes: partner work time
Student Task Statement
None
Student Response
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Advancing Student Thinking
Activity Synthesis
“¿Qué sumas tienen un valor de 7?” // “What sums have a value of 7?” (, , , , , , , )
Display .
“¿Qué observan sobre esta ecuación?” // “What do you notice about this equation?” (Each side has a 3 and a 4, but in a different order. Each side equals 7.)
Activity
Read the Task Statement.
“Van a trabajar en estos problemas de manera independiente. Yo les diré cuando sea hora de compartir con un compañero” // “You will work on these problems independently. I will let you know when it’s time to share with a partner.”
4 minutes: independent work time
“Compartan con un compañero cómo pensaron. Encuentren un compañero diferente para cada problema. Si no están de acuerdo con su compañero, trabajen juntos para ponerse de acuerdo en la respuesta” // “Share your thinking with a partner. Find a different partner for each problem. If you and your partner do not agree, work together to agree on the answer.”
3 minutes: partner discussion
Student Task Statement
En cada caso, decide si la ecuación es verdadera o falsa.
Prepárate para explicar tu razonamiento.
Si te queda tiempo: cambia las ecuaciones falsas para que sean verdaderas.
Student Response
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Advancing Student Thinking
If students circle true for an equation where the value to the left of the equal sign is the same as the first number on the right of the equal sign, consider asking:
“¿Cómo decidiste que esta ecuación es verdadera?” // “How did you decide this equation is true?”
“¿Cómo puedes usar las fichas de dos colores para representar ambos lados de la ecuación? ¿Puedes usar estas fichas para decidir si la ecuación es verdadera?” // “How can you use two-color counters to represent both sides of the equation? Can you use these counters to decide if the equation is true?”
Activity Synthesis
“¿Cuáles ecuaciones pudieron decidir si eran verdaderas o falsas sin encontrar el valor de ambas sumas?” // “Which equations could you tell were true or false without finding the value of both sums?” (Problem 1 because both sides add the same 2 numbers. Problem 2 because you can see that the number you are adding to 6 is different on each side of the equal sign. Problem 5 because is 9 and the other side of the expression is 9 and some more.)
Standards Alignment
Building On
Addressing
1.OA.3
Apply properties of operations as strategies to add and subtract.
Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6 = 6, 7 = 8 - 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2.
