Lesson 16

The purpose of this warm-up is to elicit the idea that two true comparison statements can be used to describe the relationship between two values, which will be useful when students write statements using <, >, and = in a later activity.

• Groups of 2
• Display the inequalities.
• “¿Qué observan? ¿Qué se preguntan?” // “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discutan con su pareja lo que pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• “Estas afirmaciones de comparación están escritas de diferente manera, pero dicen la misma información. ¿Cómo es eso posible?” //  “Even though these comparison statements are written differently, they tell us the same information. How can that be?” (One symbol means “greater than” and one means “less than.”)

The purpose of this activity is for students to learn a new center called Greatest of Them All. Students use digit cards to create the greatest possible number. As each student draws a card, they choose where to write it on the recording sheet. Once a digit is placed, it can’t be moved. Students compare their numbers using <, >, or =. The player with the greater number in each round gets a point. Students think strategically about place value when they decide how to use the first of the 2 cards they draw (MP7).

Students should remove cards that show 10 from their deck.

• Groups of 2
• Give each group a set of number cards and two recording sheets.
• Ask students to remove the cards with the number 10.
• “Vamos a conocer un nuevo centro que se llama ‘El más grande de todos’. Su pareja y ustedes van a formar un número de dos dígitos. Traten de formar el número más grande que puedan porque gana el jugador que tenga el número mayor. Juguemos una ronda juntos” //  “We are going to learn a new center called Greatest of Them All. You and your partner both make a two-digit number. Try to make the greatest number you can because the player with the greater number wins. Let’s play one round together.”
• Display the number cards and recording sheet.
• Invite a student to act as your partner.
• Choose a number card.
• “Puedo decidir dónde ubicar este dígito en la hoja de registro. Este dígito puede ser mis unidades o mis decenas, pero una vez que lo ubique, no lo puedo mover” //  “I can decide where to place this digit on the recording sheet. This digit can be my ones or my tens, but once I place it, it cannot be moved.”
• “¿Dónde ubicarían este número en la hoja de registro? ¿Por qué lo ubicarían ahí?” // “Where would you place this number on the recording sheet? Why would you place it there?” (I would put it in the tens place because 6 is a high number and I want to have a lot of tens. I would put this number in the ones place because I want to try to get a greater number for my tens.)
• “Después de que ubiquen un número, su compañero escoge una tarjeta y ubica el número en su hoja de registro” // “After you place one number, your partner chooses a card and places the number on their recording sheet.”
• Invite your partner to choose a card and decide where they will place the number.
• Repeat until each of you has a two-digit number.
• “Ahora comparemos nuestros números. ¿Quién tiene el número mayor? ¿Cómo lo saben?” // “Now we compare our numbers. Who has the greater number? How do you know?”
• “Finalmente, escribimos una comparación usando <, > o =” // “Finally, we write a comparison using <, >, or =.”
• Demonstrate writing the comparison statement on the recording sheet.
• “El jugador que tenga el número mayor obtiene un punto. Sigan jugando hasta que alguno obtenga 5 puntos” //  “The player with the greater number gets a point. Continue playing until someone reaches 5 points.”

• 10 minutes: partner work time

• Display a recording sheet with a 5 in the tens place for one partner and the rest blank.
• “Mi compañero tiene un 5 en la posición de las decenas. Escojo una tarjeta y veo que es un 6. ¿Dónde debería ubicar el 6? ¿Por qué lo ubicarían ahí?” // “My partner has a 5 in the tens place. I choose a card and see that it is a 6. Where should I place the 6? Why would you place it there?” (Place it in the tens place because 6 tens is more than 5 tens so the number in the ones place won't matter. You will have the greater number.)

The purpose of this activity is for students to write the symbol or number that makes a comparison statement true. Students then read the comparison statement. This activity has two parts. In the first part, students are given two numbers with a blank space in which to write a comparison symbol that makes the statement true. After students write the symbol, they read the comparison statement. Reading the statement encourages students to relate the language of comparison to the symbols (MP6). In the second part of the activity, students are given a comparison symbol and either one number or neither number. Students determine a number or numbers that will make the comparison true.

• Groups of 2
• Give students access to connecting cubes in towers of 10 and singles.

• Read the task statement.
• 8 minutes: partner work time

If students create statements that are not true, consider asking:

• “Lee tu afirmación. ¿Cómo podrías demostrar que es una afirmación verdadera?” // “Read your statement. How could you prove that it is a true statement?”
• “¿Qué otros números podrías usar para que esta sea una afirmación verdadera? Explica cómo lo sabes” // “What other numbers could you use to make this a true statement? Explain how you know.”

• Display \(\boxed{\phantom{3}} > 78\).
• “¿Cómo supieron qué número haría que la afirmación fuera verdadera?” // “How did you know what number would make the statement true?” (I knew it had to be greater than 78 because I read the statement ‘blank is greater than 78’. I put in a number and read the statement out loud to see if it was true. I chose a number with more than 7 tens so I knew it would be greater than 78.)
• Display \(39 < \boxed{\phantom{3}}\).
• “¿Cómo supieron qué número haría que la afirmación fuera verdadera?” // “How did you know what number would make the statement true?” (I knew it had to be greater than 39 because I read the statement ‘39 is less than blank’. I put in a number and read the statement out loud to see if it was true. I chose a number with more than 3 tens so I knew that it would be greater than 39.)
• Invite students to share comparisons they made for \(\boxed{\phantom{3}}< \boxed{\phantom{3}}\) and \(\boxed{\phantom{3}} >\boxed{\phantom{3}}\).\(\) For each comparison shared, have the class decide if it is true or not.