*Math expert Bon Crowder has plenty of ideas for how to incorporate math into the holiday traditions. Some of her suggestions are aimed at younger children while others are more appropriate for middle schoolers.*

Your kids are on winter break. They're having fun, playing, decorating, and being joyous. Why not sprinkle a little math into the mix? Here are some ways to connect math concepts to some holiday traditions.

#### Santa Claus

If your children believe in Santa Claus (or maybe even if they don’t), you can talk to them about Santa Math.

Suppose the U.S. had its own “dedicated” Santa Claus. Since there are about 125 million houses in the U.S., how much time would he get to spend at each house if he has to make all his deliveries in one night?

You can also calculate how many cookies “American Santa” will eat under different scenarios—having one at every other house, or two per house, for example. You can even get more advanced by asking how many calories he'd consume!

#### Ball Decorations

Christmas tree decorations come in various shapes and sizes. Use some sticky tack to hold a ball-shaped ornament on a piece of paper. Trace around it and measure across this to find the diameter and radius. Note: the radius is half of the diameter.

Use the formula V = 4/3 π r^{3} to find the volume of the ball. Do this for various balls and write down the results. Talk about how, as the radius changes, the volume of the balls also changes. In fact, if the radius doubles, the volume is multiplied by eight!

#### Eggnog

You can buy eggnog in various amounts at the grocery store. The quantities are indicated in fluid ounces, which measure volume. This is different from “regular” ounces, which measure weight.

Weigh 4 fluid ounces of eggnog on a kitchen scale. Talk about how it weighs more than 4 ounces.

Weigh 4 fluid ounces of regular milk, water, vinegar, and any other fluids you have in the kitchen, including cake batter. Compare the weights and talk about why each one would be lighter or heavier than the others.

#### Advent Wreath

An advent wreath consists of four candles arranged in a square inside an evergreen wreath circle. Get into geometry by saying, “The candles make a square inscribed in a circle!”

You can also do some fun word problems: “We burn the first candle each day for a week. On week two, we burn the first candle every day as well as the second candle. On weeks three and four we add the other two candles the same way. At the end of advent, how many days has each candle burned?”

#### Door Wreath

Wreaths are a special shape called an annulus, which is basically one circle inside another circle, forming a ring.

Measure the diameters of the outside and inside of the wreath. Find the areas of the circles using A = π r^{2} Subtract the smaller sum from the larger to determine the surface area of the wreath.

#### Dreidel Game

The rules of playing the dreidel are simple, but the probability and statistics involved are more advanced.

If you play with your kids, mention that with a “fair dreidel” there’s a 1 in 4 chance of getting a Gimel. And explain that an unfair dreidel, like an unfair die, has a different probability than 1/4 for landing on each of the four sides.

With dice we call this “loaded dice.” For dreidels, it’s just part of the fun.

#### Menorah

The eight candles making up the menorah are arranged symmetrically on each side of the shamash (the center candle). Eight is a perfect cube (2^{3} = 2 x 2 x 2 = 8), and nine is a perfect square (3^{2} = 3 x 3 = 9).

Invite your children to wonder if there are any other sequential numbers (like 8 and 9) that are perfect squares and cubes.

The holiday season is full of opportunities to learn. And at every turn, there's a bit more math you can talk about!