09/09/2026
Let Socrates show us the math insight from that picture.
Socrates: Boboy, look at the triangle on the left. Do not look at the formula yet. What do you notice?
Boboy: Every row begins and ends with 1.
Socrates: Good. Now look at the 6 in Row 4. Where did it come from?
Boboy: From the two 3s directly above it.
Socrates: And 3 + 3?
Boboy: 6.
Socrates: Look at the 4 beside it. What numbers are directly above it?
Boboy: 1 and 3.
Socrates: And their sum?
Boboy: 4.
Socrates: So if I covered Row 5, could you reconstruct it from Row 4?
Boboy: I think so.
Socrates: Try.
Boboy: It begins with 1.
Then 1 + 4 = 5.
4 + 6 = 10.
6 + 4 = 10.
4 + 1 = 5.
And it ends with 1.
So Row 5 is:
1, 5, 10, 10, 5, 1.
Socrates: Excellent. You have just built another row of Pascal’s Triangle.
Now look at the table on the right.
What is the sum of Row 0?
Boboy: 1.
Socrates: Row 1?
Boboy: 2.
Socrates: Row 2?
Boboy: 4.
Socrates: Row 3?
Boboy: 8.
Socrates: Continue.
Boboy: 16, 32, 64.
Socrates: Forget Pascal’s Triangle for a moment.
Just look at these numbers:
1, 2, 4, 8, 16, 32, 64.
What is happening?
Boboy: Each one is twice the one before it.
Socrates: Can you write them as powers of 2?
Boboy:
1 = 2⁰
2 = 2¹
4 = 2²
8 = 2³
16 = 2⁴
32 = 2⁵
64 = 2⁶.
Socrates: Now compare the exponent with the row number.
Boboy: They are the same!
Socrates: Then finish this sentence:
The sum of all the numbers in Row n appears to be…
Boboy: 2ⁿ.
Socrates: Did I give you that rule?
Boboy: No.
Socrates: Where did you get it?
Boboy: From the pattern in the picture.
Socrates: Good.
But seeing a pattern gives us a conjecture.
Mathematics asks another question:
Why should it continue?
Boboy: Hmm.
Socrates: Let us look again.
Suppose one number in a row is 6.
When we build the next row, where does that 6 contribute?
Boboy: To the number below it on the left and the number below it on the right.
Socrates: So how many times does that 6 contribute to the next row?
Boboy: Twice.
Socrates: And what about every other number in the row?
Boboy: The same thing!
Socrates: Then if every number contributes twice to the next row, what happens to the total?
Boboy: It doubles!
Socrates: Exactly.
So if Row 5 has a sum of 32…
Boboy: Row 6 must have a sum of 64.
Socrates: And the next?
Boboy: 128.
Socrates: And the next?
Boboy: 256.
Socrates: Now we are no longer merely noticing that the totals double.
We can see why they double.
Now look at the challenge at the bottom.
The picture stops at Row 6.
Suppose I ask you for the sum of all the numbers in Row 100.
Would you construct all one hundred rows?
Boboy: No.
Socrates: Would you calculate every number in Row 100 and add them?
Boboy: Definitely not.
Socrates: Then what does what we have discovered tell you?
Boboy: The sum of Row 100 is 2¹⁰⁰.
Socrates: Which answer?
Boboy: B.
Socrates: Very good.
Boboy: But Socrates, why do mathematicians care so much about this triangle?
Socrates: A better question.
Suppose there are five students and you must choose two of them for a team.
How many different pairs can you make?
Boboy: Ten.
Socrates: Look at Row 5.
Boboy: 1, 5, 10, 10, 5, 1.
There is 10.
Socrates: Coincidence?
Boboy: I am beginning to suspect that you will say no.
Socrates: I would rather you discover that yourself.
Those numbers count combinations: the number of ways we can choose things.
Now, have you studied this?
(a + b)²
Boboy: Yes.
a² + 2ab + b².
Socrates: Ignore the letters for a moment. What are the coefficients?
Boboy: 1, 2, 1.
Socrates: Find them in the picture.
Boboy: Row 2!
Socrates: And what about
(a + b)³?
Boboy: That gives coefficients 1, 3, 3, 1.
Wait.
That is Row 3.
Socrates: So where have we now found the same triangle?
Boboy: In number patterns, combinations, and algebra.
Socrates: And combinations are one of the foundations of probability.
Boboy: So Pascal’s Triangle is not just a triangle of interesting numbers.
Socrates: Exactly.
Its importance is not merely in the numbers you see.
It is in the mathematical ideas those numbers connect.
Boboy: Is that why it is called Pascal’s Triangle? Did Pascal invent it?
Socrates: Another good question.
No.
The pattern was studied by mathematicians in different civilizations centuries before Blaise Pascal. It appeared in mathematical work in places such as China, Persia, and India.
Pascal later studied its properties systematically and developed important connections involving combinations and probability.
Boboy: So even the history of the triangle has a pattern of connections.
Socrates: Mathematics often does.
And we have barely opened this triangle.
Look at its diagonals.
Look at its symmetry.
There are other familiar number patterns hiding there.
Boboy: Which ones?
Socrates: I would rather not tell you.
Boboy: Why?
Socrates: Because then you would know what I see.
I want to know what you see.
The powers of 2 were not the end of the lesson, Boboy.
They were the door.
Now look again at the picture.
What pattern can you find in Pascal’s Triangle that Socrates and Boboy did not discuss?
Write what you see in the comments.
MATH AVENUE
Visual Math. Deeper Thinking.
MATH IN PICTURES
See it. Understand it. Remember it.
Once you see it, you cannot unsee it.