Run a survey, count with tally marks, and turn the numbers into picture graphs, bar graphs and line graphs. Play, solve missions, crack puzzles and beat the clock.
Start here. Data is just information you collect, like how many children like apples. A tally chart is the quickest way to count as you go. Draw one line for each vote. Every fifth line crosses the other four, so you can count in bundles of 5.
Picture graph. Use one small picture for each vote. The longest row is the most popular. To find out how many more one row has than another, look at the extra pictures.
Bar graph. A bar is a tall picture of a number. Look at the top of the bar, then follow across to the numbers on the left. Always check the scale: if the lines go up by 5, one step is worth 5, not 1.
Line graph. A line graph shows how something changes over time, like the height of a plant each day. Each dot is one measurement. If the line goes up, the number grew. If it goes down, the number shrank.
Mean, median and mode. The mean is what you get when you share everything out equally: add the numbers, then divide by how many there are. The median is the middle number when the numbers are in order. The mode is the number that appears most often.
Try this above. In Play, add votes and watch the tally, the pictures and the bars grow together. Change the scale and see the same bars look different. In Challenge me, open "Numbers" and move one number a lot: which of the mean, median and mode changes?
A tally chart records counts with little lines. Four lines stand up and the fifth goes across them, so each group is worth 5.
Use a bar graph to compare separate things, like favourite pets. Use a line graph to show change over time, like the temperature each day.
For 2, 3, 3, 4, 8: the mean is 4 (20 ÷ 5), the median is 3 (the middle one) and the mode is 3 (it appears twice).
"Just starting" uses tally marks and picture graphs. "I know the basics" uses bar graphs with scales of 2, 5 and 10. "Challenge me" uses line graphs, mean, median, mode and choosing the best graph.
No. It is free and needs no account. Your stars are saved in your own browser.