Grade 4 · Repeat a fractional amount · 111 of 750
Repeat a fractional amount: quarters in each portion: 1; number of portions: 2
A plan for a classroom activity calls for 2 portions, each 1/4 of a unit. Find the amount needed for the original portions, 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 plan for a classroom activity calls for 2 portions, each 1/4 of a unit. First find the amount needed for the original portions. Then answer: How much supply would one additional portion require in total?
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
Multiplying a fraction by a whole count repeats the fractional amount. The denominator still describes the same quarter-unit, while the numerator accumulates the total number of quarters.
Work through the reasoning
Step 1
Identify the quantities and the task
A plan for a classroom activity calls for 2 portions, each 1/4 of a unit. The first task is to find the amount needed for the original portions. Multiplying a fraction by a whole count repeats the fractional amount. The denominator still describes the same quarter-unit, while the numerator accumulates the total number of quarters.
Step 2
Calculate the original result
2 × 1/4 = 2/4. 2 quarters form 1/2 units. The units do not become smaller just because more portions were requested.
Step 3
Complete the follow-up calculation
How much supply would one additional portion require in total? 3/4 units, which is the original amount plus 1/4.
The answer
2 × 1/4 = 2/4. 2 quarters form 1/2 units. The units do not become smaller just because more portions were requested. Follow-up: 3/4 units, which is the original amount plus 1/4.
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 plan for a classroom activity calls for 2 portions, each 1/4 of a unit. Multiplying a fraction by a whole count repeats the fractional amount. The denominator still describes the same quarter-unit, while the numerator accumulates the total number of quarters. 2 quarters form 1/2 units. The units do not become smaller just because more portions were requested.
2 × 1/4 = 2/4
03 · Reflect and transfer
Explain what changes and why.
Add one complete portion at a time. The running count is in quarters even when enough quarters have accumulated to make multiple wholes. 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.