Lesson 10

The purpose of this What Do You Know About _____? is to invite students to share what they know and how they can represent the number 15.

• Display the number.
• “¿Qué saben sobre el 15?” // “What do you know about 15?”
• 1 minute: quiet think time

• Record responses.

• “Hemos mostrado números del 11 al 19 de diferentes formas. Hemos usado dedos, tableros de 10, números escritos y expresiones. En la siguiente actividad vamos a mostrar estos números como ecuaciones” // “We have shown numbers 11–19 in lots of different ways. We have used fingers, 10-frames, written numbers, and expressions. In the next activity we will show these numbers as equations.”

The purpose of this activity is for students to fill in equations to represent decompositions of numbers 11–19 on 10-frames. Students fill in either the total or the two parts missing from the equations. When students relate the parts of the 10-frame representations and the equations they reason abstractly and quantitatively (MP2).

• Groups of 2
• “Usen los puntos para encontrar los números que hacen que cada ecuación sea verdadera” // “Use the dots to find the numbers that make each equation true.”

• 2 minutes: independent work time
• 3 minutes: partner work time

• Display the image with 18 dots and the matching equation.
• “¿Cómo descifraron el número desconocido?” // “How did you figure out what was missing?” (I counted the dots to find out how many there are altogether.)
• Display the image with 16 dots and the matching equation.
• “¿Cómo descifraron el número desconocido?” // “How did you figure out what was missing?” (I looked for the two parts. There are 10 on the 10-frame and then there are 6 more.)
• “Algunas veces el número total de puntos era desconocido. Algunas veces las dos partes eran desconocidas” // “Sometimes the total number of dots was missing. Sometimes the two parts were missing.”

The purpose of this activity is for students to complete equations to represent numbers 11–19. Students may know that 17 is 10 and 7 because of repeated practice in this unit. Students may need to use objects or drawings to represent each number and then fill in an equation. While there are many possible equations to represent each number, students have only composed and decomposed numbers 11–19 as ten ones and some more ones throughout this unit, which makes 10 + _____ the most likely way for students to fill in the equations (MP8).

• Groups of 2
• Give students access to two-color counters and 10-frames.
• “En cada caso, encuentren los números que hacen que la ecuación sea verdadera. Si les ayuda, pueden usar objetos, dibujos o tableros de 10” // “Find the numbers that make each equation true. You can use objects, drawings, or 10-frames to help you.”

• 3 minutes: independent work time
• 3 minutes: partner work time

• Invite a student who represented 17 on a 10-frame to share.
• “¿De qué forma las fichas y los tableros de 10 les ayudan a completar la ecuación?” // “How do the counters and the 10-frame help you fill in the equation?”
• “¿En qué parte del tablero de 10 ven 10? ¿En qué parte del tablero de 10 ven 7?” // “Where do you see 10 on the 10-frame? Where do you see 7 on the 10-frame?”

The purpose of this activity is for students to choose from activities that offer practice with addition and subtraction, writing numbers, and counting objects.

Students choose from any stage of previously introduced centers.

• Make or Break Apart Numbers
• Bingo
• Number Race
• Grab and Count 
• Tower Build

• Gather materials from:
  • Make or Break Apart Numbers, Stages 1 and 2
  • Bingo, Stages 1-4
  • Number Race, Stages 1 and 2
  • Grab and Count, Stage 1
  • Tower Build, Stages 1 and 2

• “Hoy vamos a escoger centros de los que ya conocemos” // “Today we are going to choose from centers we have already learned.”
• Display the center choices in the student book.
• “Piensen qué les gustaría hacer primero” // “Think about what you would like to do first.”
• 30 seconds: quiet think time

• Invite students to work at the center of their choice. 
• 8 minutes: center work time
• “Escojan qué les gustaría hacer ahora” // “Choose what you would like to do next.”
• 8 minutes: center work time

• “¿Cuál centro esperan poder seguir jugando en las lecciones que vienen? ¿Qué les gusta de ese centro?” // “What center do you hope you can keep playing in upcoming lessons? What do you like about that center?”