Who would have thought someone would name an addition fact strategy after a childhood game? When I first came across a reference to Monkey in the Middle as a name for an addition fact strategy, it evoked memories of playing this game as a child!
I have also seen this strategy referred to as in-betweens and doubles plus two. I latched onto Monkey in the Middle because the label was catchy. This makes it easy for kids to remember. It can, also, be clearly represented visually with monkey clip art.
It is helpful if your students are familiar with this game so they can make connections. The Monkey in the Middle game I recall is played with three players in a line. The two players on the ends face each other. They toss a ball back and forth over the player or monkey in the middle.
The “monkey” tries to catch the ball. When the “monkey” is successful, the player who last had the ball becomes the new monkey in the middle. This game may also be called Pig or Piggy in the Middle, Pickle in a Dish, or Pickle in the Middle.
Why Should I Teach the Monkey in the Middle Addition Fact Strategy?
The Monkey in the Middle addition facts have numbers that are two apart with just one number in between (i.e. 6 + 8). Except for 5 + 7 and 7 + 5, these equations can be solved using other common strategies. Nevertheless, Monkey in the Middle is still a concept worth understanding. It’s all about enhancing number sense. When recognized, it is quick and easy to apply.
Some of your students may be able to extend this beyond basic facts to mentally solve problems with larger numbers such as 13 plus 15 or 41 plus 43.
How Should I Introduce the Monkey in the Middle Addition Fact Strategy?
While the concept was catchy, I struggled with the best way to introduce this strategy. Initially, I tried using the placement of numbers on a number line. But, this was too abstract for my students.
Next, I considered using two colors of counters on doubles ten frames. While this demonstrates the concept in a concrete way, it is not visually distinctive.
Eventually, I encountered this blog post by the Classroom Key. Ah, I had discovered the best way to introduce this strategy. The cube towers or rods are the perfect concrete way to demonstrate visually how and why this strategy works.
I created a free work mat to help you introduce this strategy to your first and second graders. Of course, I added a monkey graphic to make the connection to the name of the strategy!
You could introduce this strategy with just the connecting cubes. The work mat and equation cards simply provide structure. This is a teacher-directed activity.
- Choose to print the color or black/ white pages.
- Decide if students will work individually or in pairs.
- Print one mat for each student or pair of students. Use card stock and laminate for durability.
- Print one teacher copy of the Monkey in the Middle equation cards.
- Provide 2 sets of 10 multi-link (the ones that link on all sides) cubes in 2 different colors for each student or pair of students.
Teach this strategy by modeling it in a small group or projecting it for a large group. Be sure your students are fluent with the doubles addition facts to 18.
- Choose an equation card.
- Use two colors of cubes to show the numbers in the equation on your mat.
- Write the equation on your mat.
- Model moving one cube from the taller rod to the shorter rod.
- Notice that each rod now has an equal number.
- Take note. You made an easier equation! You created a doubles fact!
- Write the new doubles equation and the monkey (number) in the middle of the original equation (ex. 5 + 7 is the same as 6 + 6. The Monkey in the Middle is 6.)
- Repeat with multiple equations.
Emphasize that this strategy only works with two addends that have just one number in between.
Write on the laminated mats with dry erase markers. To reuse mats that are not laminated, write the equations on a separate piece of paper or a dry erase board.
Once you have introduced this activity, it can be repeated in a center.
Click on the highlighted words, Monkey in the Middle Sample, to download this free resource from my TpT store.
Looking For More Resources?
Some students will take this strategy and run with it after your introduction. Other students will require varying levels of practice and review to successfully implement it.
I have developed a set of activities, Monkey in the Middle Resource, available for purchase in my TpT store with these students in mind.
The equation cube mats provide another concrete level activity suitable to use in a small teacher-directed group or as an independent math center. The matching cube cards with a recording sheet advance to a pictorial representation.
Use the number sequence strips to practice finding the monkey (number) in the middle of two numbers. Match the monkey in the middle equations with their corresponding doubles equations to increase facility with this strategy.
For additional practice, use the worksheets as morning work, seat work, or homework.
Check out the Addition & Subtraction section of my Teachers Pay Teachers store for even more resources, including anchor charts, flashcards, and worksheets.
Read more blog posts about addition fact strategies.
Title image photo is by Speech Language Pirates.