red - Di seguito viene proposta una risorsa didattica utile per le classi in cui sono attivi dei percorsi CLIL di Matematica in lingua inglese. La risorsa guida gli studenti nella scelta del grafico più opportuno da costruire, a parture da una tabella contenente dei dati statistici.
How to construct a graph
- Make sure you have a data table containing information.
- Figure out the types of variables involved (quantitative vs. qualitative; independent vs. dependent) then choose the appropriate type of graph: Pie Graph (use step 3); Bar Graph (use steps 4-5); Line Graph (use steps 4-5).
- For Pie Graphs:
- Make sure you have a % value for each part of the whole (Whole = 100%)
- If necessary, convert each partial amount to a percent of the total amount (part ÷ whole x 100 = %)
- Draw a circle; the complete circle shows 100% or the whole
- Divide the circle into wedges (pie slices) so that each wedge represents a % from your data table
- Label each wedge (pie slice) with its Qualitative name
- Write a descriptive title above the graph
- For both Bar Graphs and Line Graphs:
- Draw your X and Y axes, leaving at least 4 lines below the X – axis and the same to the left of the Y – axis. Make your graph AT LEAST as large as ½ of your paper. Larger is often better!
- Decide which variable should be on each axis (look in your notes). Write the name of each variable AND units next to appropriate axis, leaving plenty of space next to the axis lines.
- BAR GRAPH ONLY – Label the axis for the qualitative variable: Below (or next to) the appropriate axis, write the names of different categories of the qualitative variable, leaving some space between each name.
- Number the axes of the quantitative variables:
- Determine the complete range of data which you must graph on that axis.
ACTUAL DATA: Minimum _______________ à Maximum __________________
- Round the maximum up to the nearest multiple of 5 or 10 or 100, whichever best fits your data
- Round the minimum down to the nearest multiple of 5 or 10; it is often near zero
ROUNDED DATA: Minimum _______________ à Maximum __________________
- Count the number of lines which are marked along your axis (on the graph paper). How could you evenly number those lines, in multiples of 2 or 5 or 10 or 100 (whatever seems appropriate for your data, so that your rounded maximum ends up near the very end of the axis.
- Number the axis evenly with the multiples of 2 or 5 or whatever you decided upon. You DO NOT have to put a number next to each line on the graph paper.
PLOT THE DATA
For BAR GRAPHS:
- Make the proper height bar for each category; leave some space between each bar
- Shade or color each bar
For LINE GRAPHS:
- Plot each point from the data – each point shows a relationship between a pair of measurements on the data table. When all points are plotted DO NOT “connect the dots”.
- If the points seem to show a curve, then sketch (with a pencil) a smooth, curving line that follows the trend of all the points. Some of the points will NOT be on the curving line and that is OK!
- If the points seem to show a straight line, then use a ruler to draw a “best fit” line. Some of the points will NOT be on the straight line and that is OK. The line that you draw should have the same number of points below and above the line, and some points may be on the line itself.