This Warm-up prompts students to compare four representations of a quantity. It gives students a reason to use language precisely (MP6). It gives the teacher an opportunity to hear how students use terminology and talk about characteristics of the items in comparison to one another. During the discussion, ask students to explain the meaning of any terminology they use, such as “decenas” // “tens,” “unidades” // “ones,” “número” // “number,” and “dígito” // “digit.”

• Display Images A, C, and D.
• ”¿Dónde ven 3 decenas en cada una de estas representaciones? ¿Dónde ven 5 unidades?” // “Where do you see the 3 tens in each of these representations? Where do you see the 5 ones?"

The purpose of this activity is for students to represent a two-digit number in as many ways as they can. Students are given two number cards and use them to make a two-digit number. Students create a collection with connecting cubes in towers of 10 and singles to represent their number. Then students represent their number in as many different ways as they can on paper. Representations may include base-ten diagrams, _____ tens _____ones, and expressions that show the tens and ones.

The collections students make are used in the next activity.

The purpose of this activity is for students to represent a collection of tens and ones in as many ways as they can. Students participate in a Gallery Walk. Students visit at least four collections, represent them in different ways, and then compare their representations with their partner. Students may represent the collections in any ways they choose, such as base-ten drawings with and without showing all the ones within each ten, _____ tens _____ ones, expressions that show the tens and ones, or another way that makes sense to them, including writing the 2-digit numbers.

Students can choose which collections they would like to visit or the teacher can assign the collections. During the activity synthesis, students make connections between representations.

This activity uses MLR7 Compare and Connect. Advances: Representing, Conversing.

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 20, or estimating, counting and representing quantities. Students choose from any of the previously introduced stages of the listed centers. They are encouraged to choose the center that will be most helpful for them at this time.

• Grab and Count
• Counting Collections
• Shake and Spill
• Check It Off