Picture Graphs, Bar Graphs and Line Plots
Lessons in this chapter
About Picture Graphs, Bar Graphs and Line Plots
Data Handling adds the word represent: 3rd graders now build the graphs as well as read them, and the scales stop being one-to-one.
Read, Interpret, and Represent Scaled Picture Graphs makes the key do real work. When one symbol stands for five, a row of four symbols means twenty, and half a symbol means two and a half. Choosing a sensible scale when building one is a judgement call a child has not had to make before.
Read, Interpret, and Represent Scaled Bar Graphs is the same move on an axis. The common error is reading the number of gridlines rather than the value they represent, and building a graph is what fixes it, because the child has to decide what each line is worth.
Read, Interpret, and Represent Data on Line Plots using Data in Halves and Quarters connects two chapters: the fractions learned earlier are now data values. Marking three and a half above a number line is the first time a fraction appears as a measured result rather than as an exercise.
Read, Interpret, and Represent Scaled Picture Graphs and Read, Interpret, and Represent Scaled Bar Graphs each open as a worksheet in the page, scored as your child works, and the third lesson does the same for line plots in halves and quarters. Building a graph is where the scale stops being decoration, because the child has to decide what one symbol or one gridline is worth. Three lessons, all free.
Frequently asked questions
Reading, interpreting and representing scaled picture graphs, then scaled bar graphs, then line plots using data in halves and quarters. The word represent is what is new: 3rd graders build the graphs as well as read them, and the scales are no longer one to one. It sits in Measurement and Data (3.MD), and the line plot lesson draws on the fractions chapter.
One where each symbol or gridline stands for more than one item. If a symbol means five, four symbols mean twenty, not four.
Counting gridlines instead of reading their value. If the scale goes up in twos, a bar reaching the fourth line means eight, not four.
Because building one forces the decisions that reading hides: what the scale should be, how to label the axes, what the categories are.
Because measurements often land between whole numbers. It also connects directly to the fractions chapter, where those fractions were placed on a number line.
Big enough that the graph fits, small enough that differences still show. A scale of ten for data that ranges from 1 to 8 makes every bar look the same.