Abstract:

In this study, the number line was used as an instructional strategy and Educreations was used to support students’ verbal explanations, visual representation and conceptual understanding of the number line. Using the number line can help students understand the foundations of place value and how manipulating numbers can change the place value. This approach as an instructional strategy to explain addition and subtraction can clear up the misunderstanding of the standard algorithm. The number line and Educreations together can help students develop a well-grounded foundation for their conceptual understanding of the number system, place value, addition and subtraction, and early algebra.

Action research method was used in collaboration with a K-12 instructor and higher education instructor. Action research method seeks to solve an instructional problem as a systematic inquiry which includes reflexivity and focus on the practical to improve teaching and learning or curriculum. The purpose of this research was to examine the impact of the number line as an instructional strategy and Educreations on students’ verbal and written explanations of addition and subtraction methods.
* Does the number line increase students’ addition and subtraction problem-solving scores?
* Does utilizing the number line improve students’ verbal and written explanations of their addition and subtraction strategies?
* Does using Educreations help students’ verbally express how to add and subtract using the number line?
* Are there any increases in students’ conceptual understanding of addition and subtraction problems based on an explanation?

The participants for this research was in a second grade class (ages 7-9). Fifteen and seventeen students participated in utilizing the empty number line for addition and subtraction, . Seventeen students participated in utilizing the empty number line for subtraction.

Data collection & analysis included:
* Student written reports of how they solved three-digit addition and subtraction problems – pre-test and post-test
* Google forms questionnaire about student perceptions of using the number lines
* Educreations student video analysis when solving addition and subtraction problems using the number line
* Instructor observations and reflection

Findings:
Findings suggest that using the Number Line as an instructional method along with students’ self-made videos using Educreations help them with their verbal and written explanations and conceptual understanding of addition and subtraction problems. Pretest and posttest results were:

* Addition: Pre-test: 5 out of 15 students got the correct answer and 2 could explain the process. Post-test: 13 out of 13 students got the correct answer and all 13 could explain the process.
* Subtraction: Pre-test: 13 out of 17 students got the correct answer and only 1 student could explain the process. Post-test: 16 out of 16 students and 13 could explain the process.

It was observed that even though not all the kids used number line in the post-test (they weren’t asked to do so), they were able to explain the process of addition and subtraction process. In the post-test, students were able to describe in-depth about the actual value of the place value.

Students created their own Educreations videos to solve given addition and subtraction problems. Students were successfully able to verbally describe the process of addition and subtraction and write how to solve the problem.

Keywords:

Number line, educreations, mathematics.