GeoGebra Classroom - Interaktiva lektioner

# Having two sliders coarse/fine control the same value

## Introduction

Sometimes you ma want to allow the user to control a value both roughly and with great delicacy. The answer? Provide a fine tuning slider. (This side originally created by Jonas Hall)

## When to use

The kind of precise control this provides can be useful when:
• a user need to find or investigate parameter values and is required to search a large span of value but ultimately give a high precision answer.
• modelling.
• the task creator does not wish to give obvious clues to an answer.

## How do you do this?

The construction above uses the following KEY ELEMENTS:
• A slider controlling a number spanning the entire range: Typically the step size is 0.1 or 0.01.
• A slider controlling the fine tune range: Typically the range is from -5 times the previous step size to +5 times the previous step size and the step size is 1/100 of the previous step size.
• A number to be controlled: In This example it is c and it is the sum of the previous two numbers.
• A label, showing the value of c: This can simply be dragged from the Algebra window. If you do not wish to display the variable name, double click the text to find the definition which is the FormulaText[...] command, and change the last "true" to "false". Other labels should be hidden. Also, name the slider variables intelligently as their names will show when hovering over them. Combined with the standard multipliers for step size which are activated when you are using either Shift (x0.1), Ctrl (x10) or Alt (x100) keys in combination with the arrow keys to manipulate the selected slider, this technique gives the user full control over a dynamic range of up to 1:10^6.