Grade 6 · Signed arithmetic
Game score model: Add signed changes
Game score model investigation: add signed changes. Change the quantities, follow the motion, and explain the result using the displayed mathematical relationship.
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.
A signed change has both size and direction. Start at the original value and move right for a positive change or left for a negative one. The endpoint is a sum, while the distance traveled is the absolute value of the change. This investigation begins with starting value = -2; signed change = -4. Treat the named setting as a constructed classroom model, then explain which relationships would still hold if its numbers changed.
A relationship to keep
final = start + signed change
Read the symbols alongside the explanation. A diagram shows the relationship; the assumptions tell you when it applies.
- STEP 1
Represent the given quantities
Locate the starting value on the number line before moving; its sign identifies its side of zero.
- STEP 2
Follow the changing model
Playback traces the signed change from the starting value. Intermediate positions illustrate the motion, not extra additions.
- STEP 3
Check and explain the relationship
Check the endpoint by addition, then reverse the change to recover the starting value.
Your turn to explain
Make a prediction. Test your reasoning.
Game score model: Start at -2 and apply a change of -4. Where do you finish?
Use the values specified in the question. Reset restores the initial values for this investigation.
Compare your explanation
-2 + (-4) = -6. Reversing the change recovers -2.
Work through a full lesson
Connect the animation to a worked example and practice questions.