Activity 4 - The Little Monkey's mission (Combining gates)

Introduction

From the top of a tree, the Little Monkey (Monito) greets you with excitement:

“You’ve come a long way! You already know AND, OR, and NOT.
Now it’s time to combine them to restore energy to the Forest Sphere.”

In this activity, you will build a circuit that uses all the gates to solve a challenge.

Goal

Build and verify the logic circuit:

• The Sphere turns on if:
  • B is on, or
  • A is on and C is off.

This circuit uses NOT, AND, and OR.

Required components

• 3 Input: A, B, C
• 1 NOT Gate
• 1 AND Gate
• 1 OR Gate
• 1 Output

Simulator instructions

1. Place the components

1. Make sure you are in Edit mode.
2. In the left sidebar, select and place:

• Place A, B, C (Inputs).
• Place NOT, AND, OR.
• Place an Output on the right.

2. Connect the components

1. Connect C ➔ NOT (this creates NOT C).
2. Connect A and NOT C to the AND (this creates A AND NOT C).
3. Connect (A AND NOT C) and B to the OR.
4. Connect the OR output ➔ Output.

Guided tests

Try these combinations and verify the Output:

1. A = 1, B = 0, C = 0 ➔ NOT C = 1 ➔ A AND NOT C = 1 ➔ Output = 1
2. A = 1, B = 0, C = 1 ➔ NOT C = 0 ➔ A AND NOT C = 0 ➔ Output = 0
3. A = 0, B = 1, C = 1 ➔ B = 1 ➔ Output = 1
4. A = 0, B = 0, C = 0 ➔ both paths give 0 ➔ Output = 0

If all four match, the Sphere lights up correctly!

Truth table

Simulator

Common mistakes and how to fix them

• The output is always 0: check that the OR receives two signals: B and A AND NOT C.

What did you learn?

• Gates can be combined to create more complex decisions than a single gate can provide.
• NOT lets you invert a signal; AND lets you combine simultaneous conditions; OR lets you join alternative paths.
• The final output depends on how the gates are connected and the order in which signals are processed.

Next up

In the next mission, you will meet the forest characters again to solve bigger challenges using the same three gates.