Unit 16: Data and Graphs
Turning a pile of numbers into a bar graph, a line graph, or a single number that sums it all up.
6 topics · 24 questions
Each topic is a path, not a menu: work down it in order and every question builds on the one above. Click any of them to watch the answer draw itself.
Reading and Making Bar Graphs
- How it worksWalk me through building a bar graph from a count of 4 dogs, 7 cats, and 2 fish.
- Worked exampleFind how many more votes pepperoni got than cheese if a bar graph shows pepperoni with 12 votes and cheese with 7 votes.
- Common mistakeWhy isn't a bar that looks twice as tall always worth exactly twice the amount?
- Going furtherWhat happens to a bar graph's bars if you change the side scale from counting by ones to counting by fives?
Your turn1 of 2
A class voted for pizza toppings, and the bar graph shows pepperoni with 45 votes and cheese with 6 votes. How many more votes did pepperoni get than cheese?Reading Line Graphs
- How it worksWalk me through plotting a plant's height on Monday, Wednesday, and Friday and connecting the points with a line.
- Worked exampleFind how much a plant grew between day 2 and day 5 on a line graph that goes from 3 centimeters to 9 centimeters.
- Common mistakeWhy isn't a steep line on a graph the same thing as a big number?
Your turn1 of 2
Priya's line graph tracks her sunflower's height, going from 14 centimetres to 46 centimetres between two days. How much did the plant grow?Pictographs
- How it worksWalk me through reading a pictograph key that shows one star icon stands for 5 books read.
- How it worksWalk me through drawing a pictograph for 15 apples when each icon stands for 5 apples.
- Worked exampleFind how many stickers a pictograph shows if there are 3 and a half icons and each icon equals 4 stickers.
- Common mistakeWhy isn't every pictograph icon automatically worth just 1 no matter what the key says?
- Going furtherWhat happens to the number of icons you draw if the key changes from 1 icon equals 2 pets to 1 icon equals 4 pets?
Your turn1 of 2
A pictograph of Ben's sticker collection shows 7 icons, and each icon stands for 14 stickers. How many stickers does he have?Line Plots
- How it worksWalk me through building a line plot from 5 kids' pencil counts of 2, 2, 3, 4, and 4 pencils.
- Common mistakeWhy isn't the tallest stack of X's on a line plot always the number sitting at the very end of the line?
- Worked exampleFind how many kids answered a survey if a line plot shows 3 X's over 1 pet, 2 X's over 2 pets, and 1 X over 3 pets.
- Going furtherWhat happens to a line plot's stacks if two more kids who both have 3 pets get added to the survey?
Your turn1 of 2
A class line plot about pets shows 7 X's over 1 pet, 7 X's over 2 pets, and 9 X's over 3 pets. How many kids answered the survey?Mean: Sharing Everything Equally
- How it worksWalk me through finding the mean of 3, 7, and 8 by adding them up and dividing by how many numbers there are.
- Common mistakeWhy isn't the mean of 2, 2, 2, and 20 close to 2 just because three of the four numbers are small?
- Going furtherWhat happens to the mean of a group of test scores if you add one really high score to the group?
Your turn1 of 2
Zoe scored 21, 20, and 28 points in three games. What is her mean score?Median, Mode, and Range
- How it worksWalk me through finding the median of 5, 9, 3, 7, and 1 by putting the numbers in order first.
- Worked exampleFind the median of the numbers 4, 8, 2, 10, and 6.
- Worked exampleFind the mode and the range of the numbers 3, 5, 3, 8, and 3.
- Common mistakeWhy isn't the median always the same as the average of the smallest and biggest number in a list?
- Going furtherWhat happens to the median of a list of numbers if you add one more number bigger than all the rest?
Your turn1 of 2
Five runners finished a race in 7, 17, 29, 34, and 42 seconds, listed here from least to greatest. What is the median time?