Odd or Even? - Compare Whole, Two-Digit Numbers and Determine if They are Odd or Even

Hamburgers - Compare And Order Whole Numbers

Foreheads: a game to develop math fact automaticity in + and x

Foreheads

Objective: Develop Addition and Multiplication Automaticity

Number of Players: 3

Materials: Deck of cards

Game Objective: Collect the most cards

Procedure:

1. Setup
1. Organize students into groups of three
1. Two players are called Foreheads
2. One player is called the Leader
2. Place the students in a triangle so that they can see each other (see Figure 1)
3. Put a deck of cards in the middle of the group so that the students can pull cards easily; the deck should be face-down
4. Card Values
1. cards 2 - 10 are worth the number posted on the card
2. Jacks, Queens, and Kings are worth 10
3. Aces are worth 1
4. Variation:
1. Jack = 11
2. Queen = 12
3. King - 13
4. Joker = 0
2. Playing
1. The Leader says "GO" and the Foreheads pick up a card and place it on their forehead
1. The Foreheads should not look at the card they place on their head
2. The Leader looks at the cards on the Foreheads and states the sum or product of the two cards
3. After hearing the sum or product, the Foreheads look at each other's heads and use the card they can see to identify the card that is on their head.
1. The Foreheads call out the number they think is on their head.
4. The Leader listens to their answers and rewards the cards to the first Forehead who guesses the correct card on their forehead.
5. The Forehead who guessed first and accurately collects the two cards and places them in a neat pile in front of them.
6. Repeat steps 1 - 6 for five rounds.  
7. When 5 rounds have been completed, the Foreheads count the number of cards in front of them and the Forehead with the most cards is declared the winner.
1. A new Leader is chosen from the Foreheads and play continues until the teacher ends the activity.
3. Ties
1. If the Leader cannot tell which Forehead said their answer the fastest and both students called out accurate answers, the two cards are placed in front of the Leader.
1. Repeat steps 1 - 5 described in the playing section above.

Resource

Bay-Williams, J. M., & Kling, G. (2014). Enriching Addition and Subtraction Fact Mastery through Games. Teaching Children Mathematics, 21(4), 238–247. 

Figure 1

Subitizing Dots

Introduction

Dr. Douglas Clements, in an article written in the March 1999 Teaching Mathematics Journal wrote,

"Children who can not subitize conceptually are handicapped in learning such arithmetic processes." (p. 401)

The arithmetic processes Dr. Clements is most likely referring to are: addition, subtraction, multiplication, and division.  Students who can subitize numbers can see how many are in a set instantly.  This ability, as Clements suggests, will help students eventually solve problems such as 3 + 9 = 12 because they will have had practice composing and decomposing groups of 3 and of 9 (e.g. 3 = (2+1), (3+0), (1+1+1) and 9 = (1+8), (2+7), (3+6) etc.).

Let's see if you can subitize.  How many dots do you see in figure 1?

Figure 1

There are 3 dots displayed and it is highly unlikely that you had to count each dot to determine the quantity.  You instantly saw 3 dots and this instantaneous "seeing" is called subitizing.

Teacher Problem

So, what if you are in a classroom where many children have not developed their subitizing skills?  How would you develop them?  Well, one way is to play the "Show and Tell game" (MacDonald & Shumway, 2016, p. 345).  In this subitizing game, a teacher shows a student a "card" with a number of dots on it and the student tells the teacher how many dots they see as quickly as possible.

Here is an example of the game.

1.) Teacher shows the student this "card":

2.) Student tells the teacher they see 4 without having to count: 1, 2, 3 4 - they just "see a group of 4."

Teacher Solution

Create your own subitizing cards using Google Slides.  Take a look at this example by elementary school teacher Jake Jaroszewski.

Here is a link to Jake's Subitizing Dot Cards

One of the great things about Google Slides is that you can share your work with others, they can make a copy of it and then modify it to suit their needs.

Teachers can use these cards in a digital format or print, laminate and share them with their students to help them develop subitizing skills and increase their confidence in math.

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Resources

Clements, D. H. (1999). Subitizing: What Is It? Why Teach It? Teaching Children Mathematics, 5(7), 400–405.

MacDonald, B. L., & Shumway, J. F. (2016). Subitizing Games: Assessing Preschoolers’ Number Understanding. Teaching Children Mathematics, 22(6), 340.