Illuminations works to serve you by increasing access to quality standards-based resources for teaching and learning mathematics, including interactive tools for students and instructional support for teachers.

In this lesson, students describe order by using vocabulary such as before, after, and between.

In this lesson, students review classification, make sets of a given number, explore relationships between numbers, and find numbers that are one more and one less than a given number.

Students use buttons to create, model, and record addition sentences.

This lesson captures students’ interest, provides a review of the primary unit objectives, and assesses students’ prior knowledge.

Students work with subtraction at the intuitive level as they explore number families and ways to decompose numbers to 10.

In this lesson, students model subtraction with connecting cubes while the teacher reads to them from counting books.

A children’s book sets the stage for this lesson which encourages students to review counting back. In this lesson, children write subtraction problems and model them with cubes. They compare sets and record differences in the form of a table. The additive identity is reviewed in the context of comparing equal sets.

Students model with buttons and record addition and subtraction.

In this lesson and the following one, students investigate subtraction more directly, beginning with the easier “take away” mode.

Students explore subtraction in the comparative mode by answering questions of “How many more?” and “How many less?” as they match sets of buttons.

During this lesson, students use the mathematical knowledge and skills developed in the previous lessons to demonstrate understanding and the ability to apply that knowledge to playing subtraction games.