Grade 1 · See ten and the extra part · 326 of 750
See ten and the extra part: counters already placed: 3; counters to bring: 10
A display at a classroom activity begins with 3 counters and has 10 more ready to join. Find the total after the arriving counters join and the original missing part of ten, explain the calculation, and check a related question.
Try the question, use a hint when you need one, and compare your reasoning with the worked solution. The animation starts with this chapter’s values; changing its controls explores a new case.
01 · Make a prediction
Your practice question
A display at a classroom activity begins with 3 counters and has 10 more ready to join. First find the total after the arriving counters join and the original missing part of ten. Then answer: Before any arrivals, how many counters are needed to make exactly ten?
Use this scratch space or work on paper. Your notes stay on this page and clear when you leave. Answers are for self-checking; they are not automatically graded.
A starting point
A ten-frame has ten positions. First identify the empty positions needed to finish ten; any arriving counters beyond those positions belong in a second frame.
Work through the reasoning
Step 1
Identify the quantities and the task
A display at a classroom activity begins with 3 counters and has 10 more ready to join. The first task is to find the total after the arriving counters join and the original missing part of ten. A ten-frame has ten positions. First identify the empty positions needed to finish ten; any arriving counters beyond those positions belong in a second frame.
Step 2
Calculate the original result
3 + 10 = 13; missing part of ten = 7. 7 counters complete the original ten-frame. Compare that missing part with the 10 counters available to add.
Step 3
Complete the follow-up calculation
Before any arrivals, how many counters are needed to make exactly ten? 7, because 3 + 7 = 10. This asks about the original frame, not the full supply.
The answer
3 + 10 = 13; missing part of ten = 7. 7 counters complete the original ten-frame. Compare that missing part with the 10 counters available to add. Follow-up: 7, because 3 + 7 = 10. This asks about the original frame, not the full supply.
Compare the method as well as the result. A different valid method may reach the same answer. Keep exact values until the last step when the question asks for rounding.
02 · Explore the model
See the mathematical relationship move.
Use Play, Pause, and the timeline to inspect the construction. Reset restores the question’s original settings. The displayed assumptions describe where this model applies.
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.
The mathematical idea
A display at a classroom activity begins with 3 counters and has 10 more ready to join. A ten-frame has ten positions. First identify the empty positions needed to finish ten; any arriving counters beyond those positions belong in a second frame. 7 counters complete the original ten-frame. Compare that missing part with the 10 counters available to add.
3 + 10 = 13; missing part of ten = 7
03 · Reflect and transfer
Explain what changes and why.
Fill the first frame from left to right, then watch any extra counters enter the next frame. Each position holds one counter. Explain which quantity changes and which relationship stays valid. Use the starting values again before checking your written answer.
This is a distinct guided scenario using a reusable mathematical model. Similar-looking diagrams can represent different given values and conclusions; they are not different mathematical theories.