Start with the direct weight

The guess is $23.75. The real price is $40, so the guess needs to rise.

Start with the output weight after hidden 1. The hidden unit sends .50, and the weight is 25.

This weight sits directly beside the price, like the weights in Chapter 1.

Press raise by 1. Watch three numbers:

Raising the weight by 1 raised the price by $.50. The hidden signal was .50, so adding 1 to the weight added $.50 to the price.

Because the price was too low, increasing this weight helped. This was the easy case, because the weight touched the price directly.

Next, we will move one step earlier in the machine.

The guess is $23.75. The real price is $40, so the guess needs to rise.

Start with the output weight after hidden 1. The hidden unit sends .50, and the weight is 25.

This weight sits directly beside the price, like the weights in Chapter 1.

Press raise by 1. Watch three numbers:

Raising the weight by 1 raised the price by $.50. The hidden signal was .50, so adding 1 to the weight added $.50 to the price.

Because the price was too low, increasing this weight helped. This was the easy case, because the weight touched the price directly.

Next, we will move one step earlier in the machine.