Using Simulations for Homework

Using simulations for homework solves an old problem: the most useful science homework is an experiment, and students can't take the lab home. An interactive simulation runs on any phone or laptop, needs no equipment, and can be repeated as often as a student needs. This guide shows you how to design a homework task around a simulation, collect the answers without student accounts, handle deadlines, and use the results at the start of the next lesson. It ends with three complete homework tasks in physics, chemistry and math, with the settings to pin, the questions and the answers.

Why simulation homework works

A worksheet asks students to remember. A simulation asks them to do something, which gives you better evidence and gives them a reason to start.

• No lab needed. A student can drop two balls from 45 m, dissolve potassium permanganate until it saturates, or roll a die 1,000 times at the kitchen table.
• Repeatable. If a reading looks wrong, the student presses Reset and runs it again. In a school lab, a failed run usually means copying a partner's numbers.
• Self-checking. Number questions are checked automatically with a tolerance, so students know right away whether they read the value correctly.
• Short. A good simulation task takes 15 to 25 minutes, which leaves time for the thinking you actually want.

Simulation homework works best for practicing a measurement before a lab, consolidating a lesson with fresh numbers, and preparing a question for the next lesson. Keep long written explanations for class.

How to design a homework task

Every task in this guide follows the same five parts. Use them as a checklist.

1. One goal. Write it as something students can check: "find the fall time without air resistance", not "explore free fall".
2. Clear steps. Number them. Say which screen, which setting and which button. Students working alone can't ask you which slider you meant.
3. A data table. Give the column headings, units and the number of rows. A table tells students when they're done.
4. Number questions with a tolerance. Ask for a value read from the simulation or calculated from the table, and accept a small range around it. A tolerance stops arguments about the last digit while still catching wrong readings and wrong units.
5. Prediction first, then check. Ask one prediction question before the simulation unlocks, then the same question again after the experiment. The change between the two answers is the most useful number you'll get.

In Simulic, the questions belong to the share link. Open the simulation, set the starting values, click Share, and on the Questions tab create a question set with up to 5 questions and up to 3 predictions. The step-by-step guide to collecting student answers walks through every screen. For the teaching side, see using simulations for formative assessment.

A few writing rules save a lot of confusion at home:

• Put the steps in Instructions for students. They appear above the questions, so students see them while they work.
• Name the readout students should use: "read the terminal velocity in the line under the graph".
• Give the unit in the question and set it in the Unit field, so "3.03" and "3.03 s" are both right.
• Keep one idea per question. If a student gets it wrong, you want to know which step failed.

One link per class

Create a separate link for each class, for example "Grade 9 · Period 3 · Homework". Each link pins the language and the current settings, so every student starts from the same values. Several links can use the same question set, and the answers stay separate per class. Duplicate copies a link with the same settings and question set, without the answers, which is the fastest way to set up the next class.

Post the link the way your students already receive homework: the Google Classroom or Microsoft Teams button on the Share page, a message in your LMS, or the QR code. The guide to adding a simulation to Google Classroom covers the assignment options.

On an ordinary link, students can see and change every value in the starting-values panel under the simulation. That's fine for homework, because they need the controls. If a task depends on a hidden value, such as a mystery resistor, you need locked parameters, a Pro link option.

Deadlines

Decide in advance how a deadline will work, and tell students.

• On any plan: after the deadline, open the Share page and click Turn off link. Students who open it see that the link is no longer available, and you can turn it back on for a student who was absent. The Time (UTC) column in the results shows when each answer arrived.
• With Pro (optional): set Last day (UTC) under Options on the link. The link stops working after that day, so you don't have to remember. The day ends at midnight UTC, which is afternoon or evening in the Americas, so pick the day after if your deadline is "Thursday night".
• Answer key after the deadline (Pro): with an expiry date set, choose the feedback "Score, right/wrong, answers and explanations" and tick Show answers only after the link expires. Until the deadline, students see their score and which answers are right or wrong; afterwards they reopen the link to see the answer key. This doesn't work on password-protected links.

Expiry dates are only a convenience. Turning a link off by hand works on the free plan and does the same job.

Checking results in the next lesson

Open the results before class, not during it. Five minutes is enough.

1. On the Share page, click View answers on the class link. You see each nickname, the time, the score, the number of attempts and every answer, with the percentage correct under each question.
2. Look for the question with the lowest percentage, then read the wrong answers. A cluster of the same wrong value usually means one misread readout or one wrong unit.
3. Compare the Prediction and After columns. Count how many students changed their minds.
4. If several classes used the same set, open the set on the Questions tab and choose All classes for the percentage correct by class.
5. Start the lesson with the one question most students missed. Run the simulation on the projector and do it together.

Show the percentages, not the table of names. Students don't need to see who got what. Download CSV gives you the full table for your gradebook or for pooling class data, as in the dice task.

On the free plan you can collect 100 student answers per month across all your links. Three classes of 30 students use 90 of them with one homework, so check the counter at the top of the Share Links tab. When the limit is reached, students still see the questions, but new answers are not collected until the next month. Pro collects unlimited answers for $7 a month or $59 a year; see pricing.

Three complete homework tasks

Each task lists the link settings, the instructions to paste, the questions with answers and tolerances, and what to discuss next lesson. All values come from the simulations' own models.

Task 1. Physics: does a heavier ball fall faster?

Simulation: Free fall and fall with air resistance. Pin on the link: drop height 45 m, g = 9.8 m/s², object 1 = 5 kg, object 2 = 0.2 kg, air resistance off. Time: 15 minutes.

Instructions for students: "1. Press Drop again and watch both objects land. Read the landing times under the graph. 2. Tick Air resistance and drop again. 3. Read the two terminal velocities and the landing speeds."

Data table (student copy):

Run	Object	Landing time (s)	Landing speed (m/s)
No air resistance	5 kg
No air resistance	0.2 kg
Air resistance	5 kg
Air resistance	0.2 kg

Questions:

1. Prediction (multiple choice, ask again after): "With no air resistance, a 5 kg ball and a 0.2 kg ball are dropped together from 45 m. Which lands first?" Options: the 5 kg ball / the 0.2 kg ball / both at the same time. Answer: both at the same time.
2. Number: "With no air resistance, how long does the fall take?" Answer: 3.03, tolerance ± 0.05, unit s. Explanation: "t = √(2h/g) = √(90 ÷ 9.8) = 3.03 s for any mass."
3. Multiple choice: "With air resistance on, which lands first?" Answer: the 5 kg ball. It lands at about 3.09 s and the 0.2 kg ball at about 3.20 s.
4. Number: "With air resistance on, what is the terminal velocity of object 2?" Answer: 36.4, tolerance ± 0.2, unit m/s. Object 1's terminal velocity is 62.2 m/s.
5. Short answer: "Object 2 hits the ground at about 25 m/s. Did it reach its terminal velocity? Explain." Model answer: "No. 25 m/s is well below 36.4 m/s. It was still speeding up, just more slowly than object 1, when it landed."

Next lesson: ask why the lighter ball has a lower terminal velocity. Both balls are made of the same material, so the lighter one is smaller and has more area per kilogram. Then raise the drop height to 300 m in the starting values and watch the 0.2 kg ball level off just under 36.4 m/s.

Task 2. Chemistry: molarity and saturation

Simulation: Molarity – moles, volume and concentration. Pin on the link: copper(II) sulfate, 0.50 mol, 0.50 L, Show values on. Time: 20 minutes.

Instructions for students: "Drag the round handle on the vertical slider to change the moles and the handle on the horizontal slider to change the volume. Read C and the mass dissolved under the beaker. Record each setting in your table before you change it."

Data table:

Solute	n (mol)	V (L)	C (mol/L)	Mass dissolved (g)	Saturated?
CuSO₄	0.25	0.50
CuSO₄	0.25	0.25
KMnO₄	0.50	0.50
NaCl	1.00	0.40

Questions:

1. Prediction (number, ask again after): "You dissolve 0.50 mol of potassium permanganate in 0.50 L of solution. What will the concentration be, in mol/L?" Answer: 0.40, tolerance ± 0.01. Most students predict 1.00.
2. Number: "CuSO₄, n = 0.25 mol, V = 0.50 L. What is the concentration?" Answer: 0.50, tolerance ± 0.01, unit mol/L.
3. Number: "What mass of CuSO₄ is dissolved?" Answer: 39.9, tolerance ± 0.2, unit g. Explanation: "0.25 mol × 159.6 g/mol = 39.9 g."
4. Number: "Keep n = 0.25 mol. Which volume gives a concentration of 1.00 mol/L?" Answer: 0.25, tolerance ± 0.01, unit L.
5. Short answer: "Why does the KMnO₄ concentration stop at 0.40 mol/L?" Accepted answer: *saturat*. Model answer: "The solution is saturated. In this model only 0.40 mol of KMnO₄ dissolves per liter, so 0.30 mol (47.4 g) stays as solid at the bottom."

The last table row gives 2.50 mol/L and 58.4 g of NaCl, still unsaturated, because table salt saturates only at 6.10 mol/L.

Next lesson: compare the four solutes' saturation limits and discuss why "add more solute" doesn't always mean "more concentrated".

Task 3. Math: experimental probability with class data

Simulation: Dice and coin tosses – experimental probability. Pin on the link: six-sided die, 1,000 trials, toss speed 100 trials/s, theoretical line on. Time: 15 minutes.

Instructions for students: "Press Run and let all 1,000 rolls finish (about 10 seconds). Copy the count and the experimental probability for each face into your table. Then read the largest deviation under the chart."

Data table: one row each for Count and Experimental probability, one column per face 1 to 6.

Questions:

1. Prediction (number, ask again after): "In 1,000 rolls, how many sixes will you get?" Use the Range grading mode for the "after" answer: accept 130 to 203. The expected count is 1,000 ÷ 6 ≈ 167, and about 99.8% of honest runs land in this range.
2. Number: "What is the theoretical probability of rolling a six, to three decimal places?" Answer: 0.167, tolerance ± 0.001.
3. Number (range): "What experimental probability did you get for a six?" Accept 0.130 to 0.203.
4. Number (range): "What largest deviation does the simulation report?" Accept 0 to 0.05. Typical values are 0.01 to 0.03.
5. Multiple choice, no correct answer: "Did you get exactly 167 sixes?" Yes / No. This works as a class poll.

Next lesson: download the CSV and add up everyone's sixes. With 28 students you have 28,000 rolls, and about 19 times out of 20 the class proportion lands between 0.162 and 0.171, much closer to 1/6 than most individual results. That is the law of large numbers, made from your students' own data.

Equity: make sure every student can do it

Homework only works if every student can open it.

• Phones work. The simulations run in the browser on phones, tablets, Chromebooks and laptops. All three tasks above fit on a phone screen; a table on paper is easier than switching apps.
• No accounts. Students open the link and type a first name or nickname. There is nothing to install, no password to forget and no email address to collect. Student pages set no cookies.
• No device at home? Let students do the task in the library or before school, or run it on the projector at the start of the next lesson and have them answer on paper. The classroom simulations guide covers present mode and QR codes.
• Language. Each link pins a language. Create a second link in a student's home language with the same question set, so the labels are familiar.

Ask students for a nickname or first name only, never a full name, email or student ID. A convention such as "first name + seat number" lets you match answers to your class list. Answers are deleted after 12 months.

FAQ

Do students need an account to do simulation homework?

No. Students open your link, type a first name or nickname, and answer below the simulation. Nothing is installed and no cookies are set.

Can I set a deadline?

Yes. On any plan, click Turn off link after the deadline. With Pro you can also set Last day (UTC) so the link closes by itself, and show the answer key only after it expires.

What if a student submits twice?

Both answers appear in the results, each with its own time, so you may see the same nickname twice. Agree on a rule, such as "the first answer counts", and tell students in the instructions.

How many answers can I collect for free?

100 student answers per month across all your links. Pro collects unlimited answers.

Can students copy each other's answers?

They can share numbers, as with any homework. Tasks with random results, like the dice task, make copying obvious, and prediction questions show you what each student thought before they looked.