# Simple Geometry Ideas that Take about 20 Minutes

Water Paint Shapes

Go outside to make 2D shapes on the driveway or sidewalk. Using a cup of water and a paintbrush or rag, children can "paint" the shapes then watch the sun make them disappear.

Circles, Circles, Circles

Use circular faces (like this plunger) to make all sorts of circles. This one is messy but so fun! You can use drinking glasses, jars, or soup cans too.

Transform (adapted Copley, 2010)

Use playdough (or use homemade salt dough) to make 3D shapes then transform them into new shapes. For example, make a sphere then transform it into a cylinder by flattening the ends. Make rectangular/triangular prisms, cubes, pyramids, spheres, cones, and cylinders.

Construction Flagging Shapes

Construction flagging tape is used by construction workers to, for example, rope off a new slab of concrete in the sidewalk. It costs only a few dollars per roll and can be found in home improvement stores and online. It isn’t sticky (though the name implies this), does not tangle like yarn does, and because it must be seen from a distance, flagging tape comes in fun fluorescent colors. You can use it to learn geometry by tying the ends together to make a loop about 40 feet long. Find a wide-open space and have 4 or 5 kids grab on to the flagging (you might have to get in on the action or invite the neighbor kids over). Can you make 2D and, gulp, 3D shapes? Talking together about the attributes of the shapes and working cooperatively to create them supports purposeful math-positive vocabulary development. Most of all, it’s fun mathematics education for even the most math-panicked parents!

Hokey Pokey Shapes

Print out shapes on cardstock, enough for each child to have a set of four shapes—circle, square, rectangle, and triangle. Children stand in a circle with the cards set on the floor beside them. Sing the “Hokey Pokey” tune replacing the body parts with shape names. For example, “You put your triangle in. You put your triangle out. You put your triangle in and you shake it all about. You do the Hokey Pokey, and you turn yourself around. That’s what it’s all about!” Repeat until all the shapes have been hokeyed and pokeyed. For an added challenge, include three-dimensional shapes as well.

# Simple Measurement Ideas that Take about 20 Minutes

Catch the Clock

Practice reading an analog or digital clock. Make up a silly dance to celebrate when children notice the clock showing the hour or half hour. Record the dance and post it on my Twitter! I can’t wait to see the silly dances and the champion clock catchers.

Three Act Tasks

Three Act Tasks are short video clips with real-world math modeling sequences. The video linked here is from the UHouston Math Youtube channel. This 90-second video gets kids wondering, How many drink cups can be filled with one 2-liter bottle of soda? What other Three Act Tasks can you find online for measuring volume? Try a few together!

Grid Boxes

From the internet, print out four sheets of 1 cm grid paper. Cut the sheets into 12 × 12 grids. Have children cut one square off each corner and form an open-top box by folding and taping the corners. This box has a capacity of 100 centimeters because 100 centimeter cubes can fit inside this 10 × 10 × 1 centimeter cubed box. Using the same size grid and cutting off different sizes of squares from the corners, ask children, “What is the largest capacity box you can make? How could you figure the capacity without filling the box with cubes?”

Turtle Pond, an interactive activity on the National Council of Teachers of Mathematics website, uses simple computer programming commands to move a turtle through a maze. Try it out with children for a fun introduction to 15-, 30-, 45-, 60-, 75-, and 90-degree angles.

# Simple Number Ideas that Take about 20 Minutes

Base Ten Riddles

Play Base Ten Riddles (Van de Walle, Karp, and Bay-Williams 2019) to practice place value. Have children build the number with base ten blocks (use these onlnine base ten pieces), draw, or write as you give clues. Here are a few to get you started, then work together to make up some new riddles.

• I have 23 ones and 4 tens. Who am I? (63)

• I have 4 hundreds, 12 tens, and 6 ones. Who am I? (526)

• I have 30 ones and 30 hundreds. Who am I? (3,030)

• I am 450. I have 250 ones. How many tens do I have? (20)

• If you put 30 more tens with me, I would be 1015. Who am I? (715)

Watch McGregor, a third grader, solve a few Base Ten Riddles.

The Sum What Dice Game

Have children write the digits 1 through 9 on a paper. Take turns rolling two dice. On each turn, the player may cover either the sum rolled on the dice or any two numbers that are still uncovered and that add to the sum rolled. For example, if a sum of 8 is rolled first, the player may cover: 8, or 1 and 7, or 2 and 6, or 3 and 5. Later in the game, if the sum of 8 is rolled again and the 5 is already covered, then the player cannot use the 3 and 5 combination and must play one of the other open possibilities. When a player cannot play, they are out and have a score of the sum of the uncovered numbers. Play continues for remaining players until everyone is out. The last person to go out will not necessarily win; the person with the lowest score wins. (Stenmark, Thompson, and Cossey 1986)

Watch McGregor and first grade brother, Quinn, play

the Sum What Dice Game.

Scaled Drawings

Scaled drawings can be fun ways to integrate art with math and think about multiplication as scaling (resizing). Each person draws a simple design with straight-ish lines (pine trees, sail boats, and flags work well) on a piece of centimeter grid paper. Trade papers and “blow up” the picture by making all the lines 2 times longer. For example, if drawing a pine tree, the trunk on the original might be 6 centimeters long and 2 centimeters wide, but on the scale drawing the trunk is drawn 12 centimeters long and 4 centimeters wide. Children might have to tape together several sheets of centimeter paper to have enough space for their double-sized drawing. Now make a scale drawing that is half as big as the original. This time the pine tree’s trunk is 3 centimeters long and one centimeter wide. Display all three masterpieces together and show off how multiplication by a whole number or a fraction resizes the drawings. This is an art and math project worthy of hanging on the fridge!

Sums of Ten Go Fish

Remove the face cards from a deck of playing cards. Each player gets seven cards. The rest of the cards are the fishing pond. Players look in their hand for two cards with a sum of 10 (number bonds for 10--examples shown here). If they find a number bond, they set it aside. Take turns asking other players for the card needed to complete a number bond. For example, if you have a 5 in your hand, ask another player for a 5. If they don’t have a 5, you “Go Fish” by picking up a card from the fishing pond. The winner is the player with the most number bonds for 10 when all the cards have been used.

From Math-Positive Mindsets page 150

Math-Positive Mindsets: Growing a Child's Mind without Losing Yours is filled with quick tips for adding a bit of math to the day. Here is an example of a Pause-ative Box (a play on the word positive) with an idea perfect for kids stuck at home in self-quarantine.

From Math-Positive Mindsets page 132

# Simple Sorting, Graphing, and Data Analysis Ideas that Take about 20 Minutes

Can Sorting/Graphing

Have children clean out the pantry or food storage area and sort the cans—fruits, vegetables, soups, and so on. Children arrange the cans in rows then make comparisons. (This is a concrete bar graph, meaning it is made of real objects instead of pictures.) Use terms like most, least, more than, less than, and equal to in your discussion. Note that data analysis is all about making informed decisions. What should you buy next time you're at the store? Soup? Fruit? What do we eat a lot of and what do we turn our noses up at?

Mean, Median, and Mode Shopping List Planning

Imagine that the pantry graph showed 8 cans of soup, 10 cans of fruit, and 15 cans of vegetables. Talk with children about which measure of central tendency (median, mean, or mode) is most useful in planning a grocery trip.

• The mean would tell us the average number of each type of food in the pantry. We add up all the cans then divide by the number of categories. 8 + 10 + 15 = 33 33 ÷ 3 = 11 Should we buy 3 cans of soup and 1 can of fruit to make it “even”?

• The median describes the middle number in the data set. If we list the number of cans in each category in order from smallest to largest—8, 10, 15—the median would be 10. Would we buy 2 cans of soup to make it reach the median?

• The mode is the number that occurs most often in a set of data. In our pantry example, we have no mode because no number appears more often than any other.

Shoe Sorting/Graphing

Does your pile of shoes look like the Cutler family's? What a mess. McGregor sorted the shoes and made a real-object bar graph. Looks like we have a lot of flip flops!

Stuffed Animal Sorting/Graphing

Children can use real objects, pictures, and graphs to represent data and make simple comparisons between sets of data: “Let’s use stuffed animals to represent the pets owned by the kids in our class. Lay all the dogs in a line. Then line up the cats. We are building a bar graph with objects that represent our pets. Which type of pet is the most popular? How many more cats are there than giraffes?”

Graph Hunt

Go on a news article hunt for surveys, polls, graphs, and tables. The weather page always contains a few interesting snippets of data. How can this data help your family plan their day? Are there ways the data could be misleading? Talk with children about how data helps us make informed decisions.

Tip: You don’t need fancy math manipulatives to build understanding of data analysis. Everyday objects from the contents of your kitchen junk drawer to canned goods to shoes make simple tools for investigations. Have fun keeping math real with real objects!

# Simple Algebra Ideas that Take about 20 Minutes

Ten Bead Bracelets

Children explore patterns (that's what makes this concept algebraic) in the sums of ten (see Number Bonds illustration above). Thread a pipe cleaner through ten same-colored beads and twist the ends to make a bracelet. See the sums of 10 by sliding the beads apart. This picture shows 1 + 9.

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Penny Baggies

Learn about how a number can be pulled apart and put back together to solve problems efficiently. Penny Baggies gets kids thinking flexibly about numbers.

Commutative Bingo

Make two sets of cards numbered 4, 5, 6, 7, 8, 9 for a total of 12 cards. Each player uses their own Bingo board. A player picks two cards and multiplies the numbers. If you pick a 6 and a 5, you can decide whether to write the product, 30, in the 5 × 6 box or the 6 × 5 box, but not both. Put the cards back in the pile. The object of the game is to get 6 in a row horizontally, vertically, or diagonally. What strategy can you use to win the game?

Play Factor Game on the National Council of Teachers of Mathematics website. This game provides practice relating multiplication and division and finding factors. Players take turns choosing numbers and coloring factors. Children can play against the computer or against another person. Great for 3-5 grade.

Parents and Teachers: All these ideas are found in Math-Positive Mindsets: Growing a Child's Mind without Losing Yours. Check it out!