Category Archives: math and the world

Number Collage and Scavenger Hunt

My son and I did this project today and we had a lot of fun. More importantly it provided a great opportunity to connect numerals to the amounts they represent. It’d be a great end of year activity for a Kindergarten student or a beginning of the year review for a first grader. It focuses on number recognition and spotting the numbers 1 to 10 in the world around us.

Materials: Poster, markers, straight edge, scissors, magazines or a Smartphone and printer (we don’t really have magazines so I used my Smartphone and printed the photos inexpensively at CVS), flyers from grocery stores or other stores

For the first part of the project you are going to be going on a scavenger hunt. You need to find the numerals 1 to 10 and examples of those numbers. We used a clipboard to keep track.

I’ve done number scavenger hunts before and it is definitely a lot more fun (and easier!) if you leave the house. We found all of our numbers just by taking a quick walk around the block. But it would also be really fun at the grocery store or library. Somewhere with lots of signs and prices will make it easier. You can also just pull out a pile of magazines and catalogs and look for numbers there.

Here are some of the numerals* we spotted on our street.

Brownie points if you notice the Disney Pixar character who made it into our collage—my son was thrilled. Now to find some real life occurrences of these numbers. The best examples are the ones that occur naturally: four chairs at a table, five siblings in a family, etc.. However, if your child gets really stuck finding seven of something I won’t judge you for putting seven M&M’s in a bowl and calling it a day.


We printed all of our photos at CVS and cut them out. My son was so excited to see his toys and our neighborhood in the photos. That is one advantage of using the Smartphone over the magazines, it gives kids more ownership over the collage.

Divide the poster into ten sections and have your child carefully label them with the right number. Paste all of your numerals and examples down. We hung out finished project in the school room so we can reference it in the future.

It’s a bit messy looking but the important thing is all the conversations we had about numbers as we put it together.

*We completely ignored place value in our hunt for numbers because we haven’t learned that yet. So for the sake of this activity a 9’s digit counted whether it was in the tens or ones column. Otherwise I think it would be really hard to find all of the numbers.

Borax Crystal Snowflakes

I’ve heard of tried several crystal growing science experiments in the past but this one was my all time favorite for several reasons. First, it was cheap! I bought a box of Borax and some pipe cleaners at Walmart for $5 and now I have enough supplies for a co-op. Second, it was fast! The crystals started growing within an hour and the snowflake had formed in 4-6 hours. Yours might take longer, but you’ll definitely see the results that same day.

I did learn a lot from trying it out so here are detailed instructions with some notes and tips.



  1. Borax
  2. Pipe Cleaners
  3. A jar or container with a wide mouth
  4. popsicle stick or skewer for hanging the snowflake
  5. string
  6. scissors

Cut the pipe cleaner into 3 pieces and twist them to make a snowflake. You may want to trim it to make sure it is even. It is easier if you make your snowflake smaller so that it easily fits into the jar without touching the sides.






Bend down one pipe cleaner and attach a piece of string. Tie the string to a skewer or popsicle stick.

For the Borax solution mix 3 tablespoons Borax per 1 cup of hot water. I ended up using at least 3 cups in order to completely cover my pipe cleaner snowflake so you might be better off mixing 1/2 cup Borax with 3 cups boiling water. I needed the water to be boiling for it to dissolve the Borax. Also, be careful when measuring the Borax it spills easily as it is very light and powdering.

You can also add food coloring, although mine didn’t really show up in the final product.

Suspend the snowflake in the solution and wait.

Business Project for 1st thru 3rd Graders

I’ve been thinking a lot about math projects as a way for kids to wrap up a unit in math and try out some of their newly learned skills in a real life situation. I was looking for something for lower elementary that utilized addition and subtraction with 3 digit numbers. I trolled around Pinterest but couldn’t find what I was looking for. So….

I came up with my own.

The idea is for kids to have fun creating their own business. They have to figure out what they are selling and design their own logo.

They have to predict and list their costs and Uno cards are used to model their projected sales. Then they have to add it all up and find their profit.

The free download is here.

Business Project for First thru Third Grade

Try it out and please leave feedback below. Coming soon…a similar project for 4th-6th.

Baby Bets…using Probability

I haven’t posted in a few weeks because I have been a little preoccupied. I’m 38 weeks pregnant as of today with our second child. So we are on baby watch!

As a mathematician I’ve been wondering what my chances are of going into labor on any specific day. Of course there are so many variables…but it is still kind of interesting to think about. I found this beauty on the internet:

due date probability

To make things a little more mathematical and interesting we could ponder these questions.

  1. Did they make those calculations using theoretical or experimental probability?
  2. How do my chances of having the baby change with each day that passes?

Hmmm…so much to think about.

Systems of Equations: Free Project Download

systems project image

As I’ve been prepping students for the New SAT math section system of equations seem to be a common trouble spot for lots of students. A system of equations is when you have to solve two or more equations at the same time. This type of math is all over the new test.

I created a fun project that helps students practice solving systems of equations. It is available here:

Systems Project

It might tie in well with planning your summer vacation 🙂

Pixar in a Box: The Math Behind the Movies

Summer time is a great opportunity for some lighter math activities or projects connection math to the world. Pixar in a Box, a new course from Khan Academy, is a perfect fit.

You can find the course here.

Level 1 is appropriate for kids as young as elementary and level 2 often delves into high school math content. This would be an outstanding option for a math co-op.

Leap Years

Happy February 29th! Make the most of a day that only comes every four years…or does it?

I learned that Leap Years happen every four years but that is not accurate. They do not happen on years that are multiples of 100 like 1900 or 2100. Unless the year is also a multiple of 400. A bit more complicated than you thought, right?

How to tell if a year is Leap Year:

1. Leap years are any year that can be evenly divided by 4.

2. Unless they can be evenly divided by 100. Then they are not leap years.

3. Unless they can be evenly divided by 400. Then they are leap years.

Here are a few examples to help clarify. The year 1900 was not a leap year because it is divisible by 4 but also by 100. The year 2000 was a leap year because it is divisible by 400. And of course, the year 2016 is a leap year because it is divisible by 4 (and not by 100).

This is because the earth rotates around the sun about every 365.242375 days. So if we add an extra day every four years that makes up for that .242375. Except that about every 100 years we will end up being a whole day ahead. So we skip the leap year on those years.

Here is a graph from Math is Fun that helps you picture what is happening:

leap year

So now when someone says February 29th comes every four years you can smile, feel superior, and say “well, actually….”

The Winter Hiker

skiing and slope

This was my opener for my Algebra class this past week. Here are the discussion questions we used. Activities like this help you think about slope in a real life context.

  1. Which path do you think the hiker should definitely avoid?
  2. Which path is the easiest in your opinion?
  3. Which path leads sharply uphill?