Gap App: Fractions was designed to identify and help correct weaknesses related to basic math computation. This app starts with basic addition and subtraction and works up to adding, subtracting, and comparing fractions. The user starts off at Level 1: Addition. These problems involve adding two positive integers together. In order to progress to the next level, the user must answer five questions in a row correctly.

The levels included are:

2. Subtraction (smaller positive integer from a larger positive integer)
4. Integer Subtraction
5. Multiplication (basic times tables...positive integers)
6. Integer Multiplication
7. Factoring
8. Reducing Fractions
9. Finding the GCD
10. Finding the LCM
11. Multiplying fractions
12. Dividing fractions
14. Subtracting fractions
15. Comparing fractions

The levels were designed to be able to assess where the user needs more practice in developing the skills necessary to work with rational numbers, and include the building blocks needed to be able to manipulate rational numbers correctly.

There are two modes for interaction: "Gap Check" and "Free Play". The user starts out in "Gap Check" mode, and must successfully unlock a level in that mode before being able to access the level in "Free Play" mode.

The "Gap Check" mode keeps track of the time, the number of problems answered and the number of problems answered correctly when completing the level. This enables the user to see which types of problems they need to practice. If a user completes a level by answering the first 5 questions correctly, they may not need to spend much time reviewing the topic. But if the user gets a few problems incorrect, they know that they need to practice that skill (in "Free Play" mode). In "Gap Check" mode, the user is walked through the levels, in order. A user cannot skip around. They work on a level, complete it, and move on to the next level.

In "Free Play" mode, the user can skip around to the various levels of the game that they have unlocked. They can work out extra problems in any level, and statistics are kept (the number of problems they answer, and the number that they get correct).

The primary objective is for the user to develop the computational skills necessary to work with fractions. It also enables the user to pinpoint where they need more practice, or need further instruction. This app would primarily be used to assess the user's knowledge gap. This material is typically covered prior to middle school, so it could be used to help teachers identify gaps, and help them target assignments based on where the student is having problems (rather than just determining that a student has not mastered adding fractions, the teacher can identify where the student is having problems, and target their instruction more effectively).