Grade 3 · Division
Library bookmarks: count groups of a chosen size
At a library event, 56 bookmarks are packed in groups of exactly 7. Change the controls and explain what the animation reveals.
Predict what will happen, press Play, then pause and explain what changed. Every control also works without playback.
Watch the relationship
PausedHD animation studio
From experiment to screen.
Present a crisp Canvas scene, save a full-HD image, or capture your model as a silent video.
Understand what you are seeing
The idea behind the motion.
At a library event, 56 bookmarks are packed in groups of exactly 7. Division by group size asks how many complete groups fit. A candidate factor divides a whole number exactly only when no objects remain outside the complete groups. 8 full groups fit and 0 remain. Therefore 7 is a factor of 56.
A relationship to keep
56 = 8 × 7 + 0
Read the symbols alongside the explanation. A diagram shows the relationship; the assumptions tell you when it applies.
- STEP 1
Read the starting situation
At a library event, 56 bookmarks are packed in groups of exactly 7. Identify what each number measures before changing a control; the worked example refers to these starting values.
- STEP 2
Follow the mathematical change
Watch the group colors separate successive groups of the specified size. A final incomplete group is a remainder, not another complete package. Pause on an intermediate frame and compare the picture with the live readouts.
- STEP 3
Explain and test the relationship
8 full groups fit and 0 remain. Therefore 7 is a factor of 56. Change one input, predict its effect, and test whether the same relationship still works.
Your turn to explain
Make a prediction. Test your reasoning.
Library bookmarks: use the original situation. At a library event, 56 bookmarks are packed in groups of exactly 7. Can every object be packed into complete groups of 7, with none left over?
Use the values specified in the question. Reset restores the initial values for this investigation.
Compare your explanation
Yes. 8 groups of 7 use all 56.
Work through a full lesson
Connect the animation to a worked example and practice questions.