Curated OER
Domain: Operations and Algebraic Thinking
Practice basic operations for young mathematicians in fun ways! Using two decks of cards (Ace through 10 plus the joker), learners play "memory" by matching numbers that can be added to make 10 and writing number sentences. In another...
Curated OER
Unknown Addends (to 20): Count the Blank Boxes
By filling in the blank squares, learners complete five addition number sentences both visually and numerically. For each problem, a frame is filled with a certain number of images (turkeys, candles, etc.) and a certain number of blank...
Curated OER
Subtraction and Unknown Addends
Using images helps budding mathematicians grasp difficult subtraction concepts. In this set of three word problems, they examine sets of objects which are reflected in each scenario. To approach subtraction in a more accessible way, the...
Curated OER
Unknown Numbers in Sums and Differences - Step-by-Step Lesson
First grade mathematicians will love to monkey around with an illustrated word problem involving missing bananas. They must decide how many bananas the monkey ate by counting the remaining bananas and by counting the number Lee had and...
Curated OER
Subtraction and Unknown Addends
A brief addition word problem has learners searching for the missing addend. They read about Mr. George, who already has five gallons of fuel in his car. Knowing the car can hold eleven gallons, they compute how many gallons he needs....
Curated OER
Bears in a Box
First graders count bears to predict missing addends. They analyze the missing addend sentence: 7 + ? = 10 and count up from 7 to 10 and check to see if there are 3 bears in the box.
Curated OER
Subtraction and Unknown Addends
The missing addend strategy is helpful to young mathematicians approaching subtraction. This worksheet walks learners through the required steps, solving the problems with them. They examine situations with one addend and a sum provided,...