# Reducing Fractions with GeoGebra - Using PreRelease 3.1 - Much Easier

 NEW! See Lesson 14 for complete details (working ggb file, pdf file with complete details and screencast).
 In GGB3.1, New function: greatest common divisor - GCD[] and Problem Solved: Can use If[] command in Text. Cases:

 ALL CASES 1. You have your numerator and denominator, e.g.: numer=-2 and denom=4.2. a. To get the GCD of the numerator and denominator - Input: GCDnd=GCD[numer,denom]b. You have your reductions with absolute value - Input: numerR=abs(numer/GCDnd) and denomR=abs(denom/GCDnd)

 1st case: You want the number, but the sign only if the number is negative .3. You find sign of your fraction: textSignN=If[numer/denom>0,"","-"] (You only have sign if negative; right-click and deselect show object.) 4. In the input field type: frac=If[denomR ≟ 1, textSignN+ numerR, "\frac{" +textSignN+ numerR + denomR + "}"]== b. Right-click on frac, select Properties, the Text tab, select LaTex, click on Apply and then on Close. The "if" asks if the reduced denominator is 1; if yes, write only the reduced numerator; if no, make a fraction with the reduced numerator and denominator.

see: fractions_reduced31.ggb

Coefficients

 2nd case: You want sign and number (e.g. it is a constant coefficent)3. You find sign of your fraction: textSign=If[numer/denom>0,"+","-"](You always have sign.) 4. In the input field type: fracCC=If[denomR ≟ 1, textSign+ numerR, textSign+"\frac{" + numerR + denomR + "}"]== b. Right-click on frac, select Properties, the Text tab, select LaTex, click on Apply and then on Close. Puts the sign in front of the number or fraction.

 3rd case: You want sign, but the number only if different from 1 (e.g. it is a middle coefficent).3. (same as case 2) You find sign of your fraction: textSign=If[numer/denom>0,"+","-"] 4. In the input field type: fracMC=If[denomR ≟ 1, If[numerR ≟ 1,textSign,textSign+ numerR],textSign+"\frac{" + numerR + denomR + "}"]== b. Right-click on frac, select Properties, the Text tab, select LaTex, click on Apply and then on Close. Leaves out the number 1.

 4th case: You want sign if negative and number if different than 1(e.g. it is first coefficent)3. (same as case 1) You find sign of your fraction: textSignN=If[numer/denom>0,"","-"] 4. In the input field type fracFC=If[denomR ≟ 1, If[numerR ≟ 1,textSignN, textSignN+ numerR],"\frac{" +textSignN+ numerR + denomR + "}"]== b. Right-click on frac, select Properties, the Text tab, select LaTex, click on Apply and then on Close. If the reduced fraction is 1, just the sign and only if it is minus.

Related Topics

geogebra help fraction reduce coefficient