How to differentiate instruction in science

Why this matters

When a science class starts density, some students already know that a brick and a bag of feathers can both weigh 1 kg. Others still think heavier means bigger. Teach the lesson at one speed and the first group sits through steps they know while the second group falls behind. The unit test is often the first time the teacher sees who never caught up.

Differentiation in science, one step at a time

In mastery learning, a student moves on once they show they understand a step. A student who doesn't yet gets the idea taught a different way, since repeating the same explanation louder and slower rarely works (Guskey, ASCD).

1. Find out where each student starts
2. Move on as soon as the student shows they understand
3. Explain it a different way when the student is stuck

No teacher can check 28 students after every step and adjust for each one. In Flint, every student gets a chat with Sparky, the AI tutor, and Sparky sets the pace in each one.

One density lesson at two speeds

Lena and Sam are in the same activity at the same time. The activity has five steps, from mass and volume up to why ice floats. The bar under each name shows which steps Sparky skipped, finished or explained a second way.

Sparky starts from what the student already knowsSparky moves on, or explains again, based on the last answerStep finishedStep skipped, already knownStep explained a second way

L

Lena

Starting point: Knows mass and volume

1. Step 1: Step skipped, already known
2. Step 2: Step skipped, already known
3. Step 3: Step finished
4. Step 4: Step finished
5. Step 5: Not reached yet

Understanding check

A 1 kg brick and a 1 kg bag of feathers: which has more mass, and which takes up more space?

Lena

Same mass, 1 kg each. The feathers take up way more space, so the brick is packed tighter.

Sparky

You've got mass and volume, and "packed tighter" is what density means. Let's jump straight to calculating it. Density = mass ÷ volume, in g/cm³.

Understanding check

A rock has a mass of 150 g and a volume of 50 cm³. What is its density?

Lena

150 ÷ 50 = 3 g/cm³.

Understanding check

Water is 1 g/cm³. Does the rock float or sink, and why?

Lena

It sinks. 3 is more than water's 1.

Sparky

You've flown through steps 1 to 4, so on to the challenge. Ice is solid water, yet it floats on liquid water. Why?

Skipped two steps, reached the challenge

S

Sam

Starting point: Mixes up mass and volume

1. Step 1: Step explained a second way
2. Step 2: Step explained a second way
3. Step 3: Not reached yet
4. Step 4: Not reached yet
5. Step 5: Not reached yet

Understanding check

A 1 kg brick and a 1 kg bag of feathers: which has more mass, and which takes up more space?

Sam

The brick has more mass. It's heavier, so it takes up more space too.

Sparky

Let's start with mass. Both weigh 1 kg, so they have the same mass. Now picture it: could you stuff 1 kg of feathers into a shoebox? Which one takes up more space?

Sam

Oh. The feathers. They'd need a huge bag.

Understanding check

Same mass, but the brick is smaller. Which one has more mass packed into each cubic centimeter?

Sam

The feathers, because there's more of them? I don't get it. Can you show me?

Sparky

Try the simulation. Both boxes hold the same 10 particles. Drag the slider to make the feathers box bigger and watch what happens to the crowding.

Sam

Bigger box, less crowded. So the brick is denser!

Sparky

Nailed it. Now let's put a number to it.

Steps 1 and 2 explained a second way, then moved on

Lena skips the two steps she already knows and is on the challenge question while Sam is still on step 2. Sam gets each step explained a second way: a shoebox for volume, then a simulation for density, which Sparky built when he asked to see it. Sparky moves him on once he says the idea in his own words. Lena and Sam are made-up students, and we wrote their chats for this page. The simulation is Sparky's own.

See who is ahead and who is stuck

Students finish at different times, so the activity page shows each student's session as it happens. Sparky flags a student who keeps getting answers wrong, and the analytics list what the class still mixes up.

Set up the activity for free

The density activity is in Flint's public library, with the five steps and Sparky's pacing rules already written into its guidelines. Open it, choose Use activity to copy it into a free Flint account, and assign it to a class.

To pace a different science topic the same way, replace the five steps in the guidelines with your own and keep these lines from the library copy:

For more science activities, see Flint for science.