[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...

Practice finding the missing value in an addition or subtraction equation involving negative numbers.

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.

The famous Clockenheimer Cuckoo is missing from Clockenheimer Clocks on Main Street! Help Math Maven get it back by solving a math riddle.

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!

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...

[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...

[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...

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...

MathWorld provides a detailed definition of addition.