The Billiard Ball Problem is a beautiful exploration of a situation both natural and novel. Great for problem solving, with connections to ratio and proportion. Also check out this Billiard Ball simulator on Scratch.

## Rectangles with Whole Area and Fractional Sides

Math concepts: Fraction/decimal multiplication, area model of multiplication Materials: Paper and pencil Tags: 5.NBT.B.7, 5.NF.4, 5.NF.6, I love the question at the heart of this lesson—it’s simple but counter intuitive. This is a perfect way to let kids look for something without The Launch Consider a rectangle. If the side lengths are whole numbers, then so is the area. Do …

## What’s the biggest rectangle?

Math concepts: Area, perimeter, number patterns Materials: Graph paper, pencil Tags: 3.MD.7.a-b, 4.OA2, 4.OA.3, 4.OA.5, 4.OA.5, 5.OA.3, MP1, MP2, MP3, MP5, MP6, MP7. Of all the rectangles with a given perimeter, which one has the largest area? This simple question launches a fascinating exploration. The Launch Remind students of the definition of area and perimeter. Then pose the following question: …

## Volume Menu

Topics: Volume, surface area, multiplication, number patterns, estimation, unit conversion Materials: Menu worksheets, cubes, perspective paper (optional), rulers, pencil andpaper Common Core: 5. NBT.5, 5.MD.1, 5.MD.3, 5.MD.4, 5.MD.5.a-c, MP1, MP2, MP3, MP5, MP6, MP7, MP8 Using a Menu The idea of using a “menu” to teach math is simple: with minimal time spent on introduction, you make available a wide array of …

## Magic Triangles

Topics: Addition, Subtraction, Logic Materials: Pencil and paper Recommended Grades: 1, 2, 3 Common Core: K.OA.A.2, K.OA.A.4, 1.OA.A.2, 1.OA.B.3, 1.OA.B.4, 1.OA.C.5,1.OA.C.6, 1.OA.D.8, 2.OA.B.2, MP1. Magic Triangles are a simple addition/missing addend problem that creates opportunities for higher level thinking. Kids must place the numbers 1 through 6 on the outside of a triangle to make the numbers on each side sum to …

## Magic Squares

Topics: Addition, Subtraction, Logic Materials: Pencil and paper, Recommended Grades: 2, 3, 4 Common Core: Put the numbers 1-9 into a square so that every column, row, and diagonal adds to 15. Why We Love Magic Squares This is a truly historical problem, with roots in cultures around the world. The arithmetic looks fairly simple at first, but the problem …

## The Hundred Chart Game

Topics: addition, subtraction, strategy Materials: Two types of tokens (gems & pawns), hundreds chart Recommended Grades: 1, 2, 3 Common Core: 1.NBT.C.4, 1.NBT.C.5, 1.NBT.C.6, C2.NBT.B.5 Add and subtract 10s and 1s to pick up the tokens on the hundreds chart. Why We Love The Hundred Chart Game This game delivers tons of addition and subtraction practice in a way kids love. …

## Flower Petal Puzzles

Topics: addition, subtraction, logic Materials: Worksheets, pencil and scratch paper Recommended Grades: 1, 2, 3 Common Core: 1.OA.A.2, 1.OA.C.6, 1.OA.D.8, 2.OA.B.2, MP1, MP7 Put each number in a “petal” so each line of three numbers in a row has the same sum. Why We Love Flower Petal Puzzles This is a simple but thought-provoking puzzle. It’s a great way to …

## Math for Love Math Circle Lessons

This is a collection of some of the games and activities that are ideal for running before and after school math circles. This particular book is designed for grades 2-3, though most of the activities would work for older or younger students. The math circles are about enrichment. Our goal is that students will leave them loving math more, and …

## Dots and Boxes

Topics: Logic, Counting, Shape Recognition, Strategy Materials: Dot Paper, pencils or crayons Recommended Grades: K-2 Common Core:K.CC.B.5, K.CC.C.6, K.G.B.5, 1.G.A.1, MP1 A game of squares and strategy that is easy to learn and hard to master. Why We Love Dots and Boxes This is a classic you may remember from childhood. The game is like a more sophisticated tic-tac-toe: fun and …