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60-day mapFive-Minute AI LessonsPart 5 · Looking Inside

What's inside an AI if you open it up? — Neural networks

One dot can only multiply and add. Stack them in layers, and out comes judgment.

  • 5 min
  • Put it in order
  • Quiz · 3

1 · Think first

Inside an AI are dots stacked in layers, passing numbers to each other. That's called a neural network.

What one dot does is surprisingly simple. It multiplies the incoming numbers by weights and adds them all up, and if the total clears a threshold, it passes it on to the next layer.

The smarts aren't inside any one dot. As the numbers pass through layer after layer, simple math piles up into complex judgments.

2 · Experiment · Put it in order

Try it — What happens inside a neural network, in order

Tap the mixed-up pieces in the right order. Three sets: what one dot does, the path through the layers, and how the weights get set.

Tap the pieces below in the order you think is right.

Figure

From input to output, through the layers

A neural network is numbers changing shape as they pass through one layer after another.

Input layerTurned intonumbersTimesweightsDifferent foreach linkThresholdMust pass tosend signalNext layerDoes the sameagainOutputlayerComes down toone answerWithout the threshold, no matter how many layers you stack, it all ends up the sameas multiplying and adding once. This step that decides whether to pass or not isKey idea: multiply, add, clear the threshold — the same bundle, repeated in every layer
Numbers flow from left to right. The orange box in the middle is what makes stacking layers mean something.

3 · Quiz

Quick check

Three questions. Pick an answer and it's marked right away, with the reason why.

Today in one line

Today in one line

One dot can only multiply and add.
Stack them in layers, and out comes judgment.

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