youcubed: Placing Chips (1-2)
youcubed (Stanford University)

In this activity students explore place value and number relationships.

Illuminations: How Many Buttons?
Illuminations (National Council of Teachers of Mathematics)

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.

Illuminations: Fact Families
Illuminations (National Council of Teachers of Mathematics)

In this lesson, the relationship of addition to subtraction is explored with books and with connecting cubes.

Illuminations: Pyramid Power
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students make sets of a given number, explore relationships between numbers, and write numbers that name how many elements are in a group.

Illuminations: Fact Family Fun
Illuminations (National Council of Teachers of Mathematics)

In this lesson, the relation of addition to subtraction is explored with fish-shaped crackers.

Illuminations: Whale Weight
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students investigate relationships between numbers, identify number patterns, represent the information in graphic chart form, and generalize the results of an investigation.