Illustrative Mathematics
Shake and Spill
Entertaining as well as educational, this math activity about decomposing numbers is bound to capture the engagement of young learners. Given a cup and five two-color counters, young mathematicians simply shake and spill the cup,...
Illustrative Mathematics
Christina's Candies
Help Christina figure out how many chocolate and lemon candies she has with a lesson on decomposing numbers. When presenting this context to the class, the teacher chooses the total number of candies and the number that are chocolate,...
Illustrative Mathematics
What’s Missing?
Now you see them, now you don't! This fun peek-a-boo activity engages young mathematicians in developing their ability to compose and decompose numbers. After being presented with a series of counters, children close their eyes while the...
Illustrative Mathematics
A Bobbie Bear's Buttons
Young mathematicians help Bobbie Bear pick colored buttons out of a box as they learn how to decompose numbers less than 10 into pairs of smaller numbers. To support students with the process, consider creating a worksheet or graphic...
Illustrative Mathematics
Pick Two
Learning to break apart numbers into smaller pairs is a critical step young mathematicians take as they develop their number sense. To practice this skill, children are provided with sets of three numbers and are asked to pick the two...
Illustrative Mathematics
Make 9
Learning how numbers are put together as parts and wholes is a big step in building the foundational number sense of young mathematicians. Here, children are given a number less than 10 and are asked to find as many pairs of numbers as...
Illustrative Mathematics
Hitting the Target Number
Make combinations to reach the target. Learners play a game to add and subtract numbers between 0 and 10 to reach a target number between 10 through 20. Teachers use the game to help pupils learn efficient ways to add and subtract within...
Illustrative Mathematics
Overlapping Rectangle
Challenge young mathematicians' ability to compose and decompose shapes with this fun geometry puzzle. The goal is simple, locate all of the rectangles shown in a picture of three overlapping rectangles. Perform this activity as a whole...
Illustrative Mathematics
Finding Areas of Polygons, Variation 1
An exercise in finding the area of polygons by decomposing into triangles and composing into rectangles is the focus of this resource. Make several copies of the worksheet for each participant. Ask learners to use colored pencils to...
Curated OER
Finding the Area of Polygons
Third graders are exposed to finding the area of polygons by decomposing figures and recomposing them into rectangles. This strategy allows children to expand on their prior knowledge of constructing shapes by rearranging parts into...
Illustrative Mathematics
6.EE.4 Equivalent Expressions
Straight to the point, learners are asked to compare a set of five expressions, determine which are equivalent, and then write equivalent equations for those that do not have any. A benefit is that they will review using properties...
K-5 Math Teaching Resources
K 5 Math Teaching Resources: Decompose a Factor [Pdf]
Students will learn how to determine the product by decomposing the factors.
K-5 Math Teaching Resources
K 5 Math Teaching Resources: 2 Digit Addition Split [Pdf]
Students will decompose double digit numbers to add numbers together.
K-5 Math Teaching Resources
K 5 Math Teaching Resources: Subtraction Split [Pdf]
Students draw a card then decompose the given numbers before subtracting them.