Fall leaf sort and graph: a 30-minute math activity for K–2

1. Outside, each pair collects 8 to 10 leaves from the ground. Pick up only fallen leaves, and wash hands afterward.
2. Back inside, each pair sorts its leaves into groups. Before they share the rule, another pair tries to guess it: "You sorted by color!"
3. As a class, pick one rule, such as color. Tape three or four columns on the floor and label the bottom of each with a sticky note: red, yellow, brown, green.
4. Students place leaves one per square, starting at the bottom of the right column. Once, on purpose, leave gaps in one column so it looks taller, and ask what went wrong. Equal spacing is what makes a graph fair.
5. Ask: "Which color has the most? The fewest? How many more yellow than red?" Count together and write the number at the top of each column.
6. Re-sort the same leaves by a new rule (big and small, or smooth and jagged edges). The graph changes, but the total stays the same. Ask students why.

For younger students: use only two columns and compare with "more" and "fewer". For 2nd grade: students copy the floor graph onto squared paper as a bar graph with a title and numbers, then write one "how many more" question for a partner. For English learners: post the color and size words with a leaf taped beside each so students can point and say them. For students who dislike the feel of leaves: let them place the sticky-note labels or move leaves with tongs.

Quick check: hold up one new leaf and ask, "Where does this go, and what will that column's number be now?" Students show the new number with their fingers.

If you try it, tell us which sorting rule your class invented that you didn't expect.