Louisiana Grade 3 Math

How many more books are in the two smaller categories together?

A fictional classroom shelf has eighteen fiction books, nine history books, and fifteen science books. The graph below uses a scale of three books per interval. Compare the combined history and science total with the fiction total. This original example asks for two connected calculations, rather than the difference between only two bars.

Use the scale in both calculations

The history bar reaches nine and the science bar reaches fifteen, so their combined total is 9 + 15 = 24 books. Fiction has eighteen books. The combined categories therefore have 24 − 18 = 6 more books than fiction. The answer should identify which quantities were compared: history and science together have six more than fiction. On the graph, history spans three intervals and science spans five. Their eight intervals represent twenty-four books, not eight books, because each interval stands for three.

Check the meaning of each step

Subtracting fifteen from eighteen gives three, but that compares fiction with science alone. Adding all three categories gives forty-two books, a total for the whole shelf. Neither calculation answers the stated question. Before calculating, circle the two categories to be combined and underline the category used for comparison. An explanation can connect the first step with a combined quantity and the second with how much that quantity exceeds another.

Avoid an unscaled drawing

Equal distances on the axis must represent equal increases. Labels of zero, three, six, nine, twelve, fifteen, and eighteen are equally spaced here. A bar for nine reaches halfway to eighteen because nine is half of eighteen. Drawing bars by counting one book for each interval would disagree with the scale. Students can check a graph against the stated totals and correct the representation before doing the comparison. Category names alone do not determine bar lengths.

Try a changed shelf

Add three history books while keeping the other categories unchanged. The history bar extends one more interval to twelve. History and science then total twenty-seven, nine more than fiction. Explain why the comparison increases by three. Use this task as an entry point to drawing and interpreting other scaled graphs in the school’s Grade 3 sequence. The fictional counts supply clear arithmetic; they are not observations from a surveyed Louisiana classroom.

Selected references from Louisiana mathematics standards

The Louisiana mathematics standards directory lists current and updated standards. For 2026–27, use the current K–12 document, updated December 21, 2017; the revised standards have full implementation in 2027–28. These selected references identify the worked activity’s focus. The expectations include numbered requirements, examples, and mathematical practices. Read the full document and confirm the school’s current instructional sequence.

Sources checked October 6, 2026. Read complete requirements, clarifications, limitations, and mathematical practices alongside the school’s sequence. This selected activity is an entry point for instruction.

Connect the explanation with practice

Use the lesson, worksheet, and quiz directory to choose a related skill. The existing resource links remain available; open each activity’s directions to understand its timer, tools, question count, and scoring.

Grade 3 is within Louisiana’s general LEAP mathematics testing range. The linked learning resources have their own directions and scoring; a practice score does not establish an official state performance level. Read Louisiana’s assessment overview.

Keep one example of the student’s reasoning with the practice result. Choose a smaller model, a related question, or a new context according to the difficulty revealed in the worked activity.