The purpose of this activity is for students to count out a given number of objects and determine the new amount if 1 more is added or if 1 is taken away. Students may count the objects each time or may use their knowledge of the count sequence to determine the new amount (MP8).

• Display the number 14 and 14 counters.
• “Mai tiene el número 14. Su pareja decidió agregar 1 ficha más. ¿Cuántas fichas tiene Mai ahora? Sin contar todas las fichas, ¿cómo lo saben?” // “Mai has the number 14. Her partner decided to add 1 more counter. How many counters will Mai have now? How do you know without counting all the counters?” (15, I know that 15 comes after 14 when we count. 15 is 1 more than 14.)

The purpose of this activity is for students to practice using the count sequence to recognize 1 more or 1 less than a number. Students should have access to counters if needed to determine 1 more or 1 less than the given number.

An alternative version of the game is introduced in the Lesson Synthesis, which students may wish to play.

• Display 17.
• “Clare y su pareja lanzaron cubos y obtuvieron un 17 y 1 menos. ¿Cómo pueden descifrar cuál es el número nuevo de Clare?” // “Clare and her partner rolled a 17 and 1 less. How can you figure out Clare’s new number?” (I just know that 16 is before 17. I know 6 is 1 less than 7 so 16 is 1 less than 17.)
• “¿Cuáles números no colorearon? Escojan uno de los números y díganle a su pareja una forma en la que hubieran podido cubrir ese número” // “Which numbers didn’t you color? Choose one of the numbers and tell your partner one way that you could have covered that number.” (I could have covered 12 if we rolled 11 and 1 more.)

The purpose of this activity is for students to choose from activities that offer practice with number and shape concepts. Students choose from five centers introduced in previous units. Students can choose to work at any previously introduced stage of these centers:

• Fewer, Same, More
• Math Fingers
• Tower Build
• Math Stories
• Which One?

To reinforce the learning of the lesson, students who choose the Fewer, Same, More center should use the less, same, more mat, with two sets of number cards 1–20. Students choose a number from one set of cards and place it at the top of the mat. Taking turns, each partner picks a card from the other set, decides if the number is less than, the same as, or more than the original amount, and places the card with the correct group on the mat.

Students will continue to choose from these centers in upcoming lessons. Keep the materials from each center organized to use each day.

• “¿Por qué les parece divertido trabajar en los centros?” // “What makes working in centers fun for you?”