The purpose of this activity is for students to reason together about the relative position of numbers on the number line. Students place number cards on the number line, which is represented by yarn strung across the classroom. Students reason about where their number should be placed based on their understanding of the count sequence and by reasoning about the relative distance of numbers from 0 and each other. As more numbers are called, students revise their number locations to be more precise (MP6, MP7). Throughout the activity, encourage students to reflect on the length between numbers and whether it is an accurate representation of the number relationships.

It is recommended that students are called in a random order. This will provide students opportunities to revise their thinking about the position of their number when more information is added to the number line representation.

• “Las rectas numéricas representan la longitud de los números desde 0 y nos ayudan a ver qué tan cerca están los números entre sí” //  “Number lines represent the length of numbers from 0 and help us see how close numbers are to each other.”
• “¿Cómo ajustaron la ubicación de su número a medida que se agregaban más números?” // “How did you adjust the location of your number as more numbers were added?” (Sometimes we had to make more room or move cards because the new number needed to fit in between numbers. The more numbers that were already on the number line, the easier it was to be precise.)
• “Al examinar nuestra recta numérica, ¿qué ajustes finales se pueden hacer para que nuestra recta numérica sea más precisa?” // “Looking at our number line, what final revisions could be made to make our number line more precise?”

The purpose of this activity is for students to analyze number lines to determine whether they represent numbers within 10 as lengths from 0. Students analyze number line diagrams that do not have equal unit intervals or have tick marks that are not properly labeled. Students discuss what needs to be added or changed in order to make these number line diagrams accurate (MP3, MP6).

This activity uses MLR8 Discussion Supports. Advances: speaking, conversing

• “¿En qué se parecen y en qué se diferencian la recta numérica de _____ y la regla?” // “What is the same and what is different between ____’s number line and the ruler?”
• “¿Cómo puedes usar la forma en que están espaciadas y numeradas las marcas de un regla para describir cómo puede  _____ ajustar su recta numérica?” // “How could you use the way the tick marks are spaced and labeled on a ruler to describe how ____ could revise their number line?”

• Display Jada’s number line diagram.
• Select previously identified students to share how Jada should revise her number line.

• Support student use of “length” to describe revisions. For example, revoice the student statement “the numbers are wrong” as “the numbers do not show the correct lengths from 0.”
• Consider asking:
  • “¿Qué cosas hizo bien Jada cuando representó los números del 0 al 10 en una recta numérica?” // “What are some things Jada did well when representing the numbers 0–10 on a number line?” (All of the numbers were listed and are in order. She started with 0 and used tick marks. The tick marks are equally spaced.)
• If time permits, repeat for each diagram.