In this section, students learn to see adding as putting together two groups and counting the total number of objects. Students see subtracting as taking away a number of objects from a group and counting the number of remaining objects.

Students represent combining and removing using physical objects. No stories or contexts are used, so students can focus on the actions of putting together, adding to, and taking from. The language “add,” “put together,” “subtract,” and “take away” is used throughout the section to describe addition and subtraction.

Students learn to interpret a phrase such as “5 and 3” to mean combining two groups (5 in one group and 3 in the other) and a phrase such as “5 take away 3” to mean finding the number of remaining objects (remove 3 objects from a group of 5). They also hear language that describes the result of those actions, such as: “5 and 3 is 8” and “5 take away 3 is 2.” No symbolic notation is used at this point.

Students also encounter and count groups of images in scattered configurations for the first time. This task highlights the need to keep track of what has been counted.

To keep track of the dots in this example, students may count all the black dots first and then the white dots or cross off dots as they count. They may also count in no particular order. Students see that although they may count the dots in a different order, they arrive at the same total.

In this section, students formally work with expressions for the first time. Students match expressions, such as and , to story problems and drawings. Students articulate why an expression represents a given problem or drawing. While students fill in addition and subtraction expressions, they are not expected to produce expressions independently in this section.

Students then transition from expressions that represent story problems or drawings to expressions without a context. To find the value of expressions, students may add or subtract in a way that makes sense to them, reasoning with fingers, objects, or drawings.

With repeated experience, students begin to notice regularity when adding and subtracting (MP8). For instance, they see adding 1 results in the next number in the count sequence and adding 0 results in the same number.

In this section, students represent and solve Add To, Result Unknown and Take From, Result Unknown story problems.

Students begin by acting out and representing stories without a question. Questionless story problems encourage students to focus on the context and action in the story, without placing focus on solving the problem. Story problems should be displayed to develop concepts of print, but students are not expected to read problems independently. The teacher reads story problems aloud, and repeats the story as needed.

There were 5 students jumping rope at recess.
2 more students came out to play with them.

Students represent the problems with objects, tools, drawings and numbers, focusing on explaining how their representation connects to the story. Students can represent problems in any way that makes sense to them. As the section progresses, students notice organizing drawings or objects makes it easier to explain how their representation connects to the story.

Students are also introduced to the concept of 0 representing a count of no objects. This idea may be abstract to students, so it is introduced in Take From, Result Unknown story problems, where taking objects away leaves no remaining objects.

Students begin seeing expressions, written by the teacher, as a way to record the action in the story. For instance, as students describe what happens with their counters, the teacher writes the expression representing their work. The teacher continues to use the language of “4 and 3” and “7 take away 5,” and introduces reading expressions as “4 plus 3“ and “7 minus 3."  Students are not expected to produce or find the value of expressions in this section.