Decimal Numbers GSP

Decimal numbers introduced in 5^th grade after fractions topic is learned. Decimal notations, the whole and decimal parts, tenths, hundredth, and thousandths are the terms given in 5^th grade. Writing and reading decimal notations, understanding meaning and function of decimal point, understanding the relationships between the numbers following one another and place value, and determining the names of the places are expected from students in 5^th grade in terms of the Turkish national mathematics curriculum. In 6^th grade, solving the numbers given in the form of decimal, rounding decimals and estimations of the results of the operations with decimals are among the objectives. The decimal notation is under the rational numbers topic in 7^th grade as notations or repeating numbers. Finally,   we can see decimals in square root topic in 8^th grade.

This decimal number applet can be effectively used especially in 5^th grade and 6^th grade. It is appropriate to meet the objectives; and it can minimize misconceptions of students. It allows students a deeper understanding about decimals. For example, students can examine that ten times 0,01 form 0,1 and ten times 0,1 forms 1. So it contributes place value concept. One common misconception about decimals is that students consider the number which is longer is bigger than the number which is shorter in look. For example, students tends to say that 0,004 is bigger than 0,4 . This applet is useful to show that 100 times 0,004 forms 0,4 that’s to the animation property. Another common misconception is that students can not predict the next number correctly. For instance, they think that the next number of 0,9 is equal to 0,10 rather than 1. This applet has decimal notations and enables us to display the next number, so we can overcome this misconception. Moreover, it can be used to teach rounding as well as estimation. Students can round numbers using this applet because it displays the point on a number line that students can see the number and its closeness to which value to round it. They can estimate the value of a given point and then closing the place the number is locating they can see the value of the number.

 The applet can be used by teachers in middle school math classes effectively. For the younger students, the teacher uses the applet to present the topic. As I mention above, it is appropriate to the objectives. Teachers can use this applet to introduce the decimals. Also they can use it in their class by expecting their students to make some constructions. For example trunc function is so useful for rounding. The teacher can choose choices under the file and determine the units that they want. Then when they use trunk for a number, they can find the rounded version of the number.