CK-12 Foundation
Ck 12: Elem Math: Adding, Subtracting, and Multiplying Missing Number
[Free Registration/Login may be required to access all resource tools.] A learning module where students must apply the order of operations to find the missing numbers in equations involving addition, subtraction, and multiplication. A...
Khan Academy
Khan Academy: Addition & Subtraction: Find the Missing Value
Practice finding the missing value in an addition or subtraction equation involving negative numbers.
Khan Academy
Khan Academy: Addition & Subtraction: Find the Missing Value
Practice finding the missing value in an addition or subtraction equation involving negative numbers. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Math Drills
Math drills.com: Algebra Worksheets
Download these worksheets to sharpen your algebraic skills. Sheets focus on missing numbers, translating, simplifying and evaluating algebraic phrases, rewriting formulas, solving linear equations, systems of linear equations and inverse...
Khan Academy
Khan Academy: Find Missing Divisors and Dividends (1 Digit Division)
Find missing divisors and dividends in 1-digit division problems. Quotients are less than or equal to 10. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video tutorial, or receive hints....
Scholastic
Scholastic: Math Maven's Mysteries: The Cuckoo Caper
The famous Clockenheimer Cuckoo is missing from Clockenheimer Clocks on Main Street! Help Math Maven get it back by solving a math riddle.
Scholastic
Scholastic: Math Maven's Mysteries: The Case of the Hatcher Hotel Heist
Help Math Maven solve this mystery! Items are missing from several hotel rooms, but some addition and subtraction clues have been left behind. Use your skills to figure out where the thief will strike next!
National Council of Teachers of Mathematics
Nctm: Figure This: Which Is Worth More, a Smile or a Frown?
Solve for the value of the smiles and frowns to find out how much a smile is worth, in this activity. A challenge that focuses on number sense, number combinations, and unknowns. Included are examples of how this skill is applied in real...
CK-12 Foundation
Ck 12: Elem Math: Balancing the Equations Numbers to 1000
[Free Registration/Login may be required to access all resource tools.] The video shows how to use addition and subtraction to keep an equation balanced by working backwards to determine the missing value. The video is followed by...
Illustrative Mathematics
Illustrative Mathematics: Cave Game Subtraction
The purpose of this task is for students to practice creating and memorizing subtraction equations while focusing on missing addends. After modeling the activity with the whole class, this game would be perfect for centers and small groups.
Illustrative Mathematics
Illustrative Mathematics: Boys and Girls, Variation 2
Students are asked to solve a word problem with both addends unknown. They will write an equation and draw a picture to use to explain their answer.
CK-12 Foundation
Ck 12: Elem Math: Add and Subtract to 100 Mixed Operations and Word Problems
[Free Registration/Login may be required to access all resource tools.] This is a set of practice problems where students solve addition and subtraction problems in order to determine missing numbers to keep the equation balanced. When...
Oswego City School District
Regents Exam Prep Center: Truth Value of Open Sentences
What happens when there is not enough information to solve a problem? Find out at this test prep site, how missing information or "open sentences" can change the value or truth of a math equation. Practice understanding and applying this...
Math Slice
Math Slice: Heavy Slice Special Test
A concise test for assessing number sense using weights and scales. Assessment is scored online offering students immediate feedback. Can be used for a quick assessment.