# Math in Action: N is for Negative Numbers

Negative numbers are a difficult concept for children to grasp, especially young children. It’s hard to understand what having less than nothing actually means. However, negative numbers are part of Math curriculums – there’s just no escaping them. So, for our STEAM series our Math in Action: N is for negative numbers.

This Math in Action consists of two activities. The first activity is focused on helping the children understand that negative numbers are used in everyday life. First, we discussed how temperatures could get “below zero” during certain times during the year. And the final activity was a number line game to reinforce that numbers go in both positive and negative directions.

Activity One: “How Hot or Cold is it?” A Negative Number Discussion

One of my preschoolers filling in her thermometer with the temperatures throughout the year.

Objective: To show the children how we use negative numbers to measure “real-world” events.

Materials:
One “How Hot or Cold is It?” printable, available here.

The average temperatures for the area for each month in the year
Markers, crayons, or colored pencils to record the temperatures

Method:
Begin by discussing the paper thermometer. What it is used for,  how to read it, etc. Talk about why people measure the temperature and how that helps us know what clothes we need to wear, what activities we can do, and even what time in the year it is.

Now, write (or have the children write) 0 for freezing and 100 for boiling. (The activity works best if the Celsius scale is used).

Next, have the children write the average temperatures for each month of the year. When an average goes below freezing (for us that’s December through February) ask if there can be less than nothing? Discuss how the numbers less than nothing tell us that the temperature is below freezing.

Activity Two: The Number Line Race

Objective:
To introduce children to the number line and the movement of numbers along the number line through the addition of positive and negative numbers.

Materials:
One Number Line Game printable for each pair of students, available here.

A different colored marker for  each student
A dice for each group of two playing. (The number of sides can be increased depending on the student’s counting ability).

Version One: Younger Children
In this version, one child is designated the positive numbers and the other the negative numbers. The goal is to get to the end of the number line first. Each child takes a turn rolling the dice. They then move that many dots in their direction. Once they have moved the correct number of spaces, make a line. Continue from the new line each turn.

My two preschoolers playing the Number Line Race.

Version Two: Older Children
In this version, each person is still designated a positive or negative. However, with each dice roll, the marker moves from where it was last. So, if the marker was at -7, and the roll on the dice was +4, then the new mark would be at -3. The winner of the game is the side who can pull the marker the furthest on their side of the number line in 15 turns.

The final game board with my first grader. We used equations to show how to write out the jumps on the number line.

All my children enjoyed these games. My first grader loved writing out the equations and solving the equation before moving the marker.  My preschoolers loved pretending it was hot or cold depending on the month.  These were fun ways to introduce negative numbers to my children.