Instructions
Welcome, Secret Agent! Your mission is to crack five mathematical codes by finding the missing unknown numbers (N) in each section. Read all instructions carefully and use your math skills (addition, subtraction, and multiplication) to succeed.
- Complete Section 1: Quick Facts Warm-up.
- Use Section 2 to solve for the Unknown Number (N) in each equation.
- Solve the real-world Agent Scenario Word Problems in Section 3.
- Attempt the optional Challenge Code in Section 4.
Section 1: Quick Calculation Training (Warm-up)
Solve these basic calculations quickly to warm up your brain.
- 8 + 7 = ____
- 25 - 9 = ____
- 4 x 6 = ____
- 15 + 15 + 15 = ____
- 52 + 18 = ____
Section 2: Finding the Missing Number (N)
In these missions, 'N' stands for the hidden number you must find. Remember, you can use subtraction to solve addition problems, and addition to check subtraction problems.
| Operation | Equation | Missing Number (N) |
|---|---|---|
| Example | 12 + N = 18 | 6 |
| Addition | 35 + N = 50 | |
| Subtraction | 60 - N = 15 | |
| Addition | N + 23 = 45 | |
| Subtraction | 91 - N = 70 | |
| Addition | 100 + N = 135 | |
| Multiplication | 5 x N = 45 |
Section 3: Agent Scenario Problems
Use your knowledge of the unknown number to solve these real-world spy scenarios.
- The Fuel Tank: Agent K needs 75 liters of fuel for his mission jet. The tank already has 42 liters. How many more liters (N) must be added?
Equation: 42 + N = 75
N = ____ liters
- The Gadget Budget: Agent J was given $150 for new gadgets. After buying a laser pen for $65, he has $N left over. How much money (N) does Agent J have left?
Equation: 150 - 65 = N
N = $____
- The Fingerprint Files: Agent L needs to sort 8 sets of fingerprint files. Each set has the same number of files (N). If she sorts 40 files in total, how many files are in each set?
Equation: 8 x N = 40
N = ____ files
Section 4: The Final Code Challenge (Optional)
This challenge involves multiple steps. Solve the first equation, then use that answer to solve the second one.
Step A: Find the value of X.
4 x 8 = X
X = ____
Step B: Use the value of X to find the value of Z.
X + Z = 50
Z = ____
Answer Key
Section 1: Quick Calculation Training (Warm-up)
- 8 + 7 = 15
- 25 - 9 = 16
- 4 x 6 = 24
- 15 + 15 + 15 = 45
- 52 + 18 = 70
Section 2: Finding the Missing Number (N)
| Operation | Equation | Missing Number (N) |
|---|---|---|
| Example | 12 + N = 18 | 6 |
| Addition | 35 + N = 50 | 15 |
| Subtraction | 60 - N = 15 | 45 |
| Addition | N + 23 = 45 | 22 |
| Subtraction | 91 - N = 70 | 21 |
| Addition | 100 + N = 135 | 35 |
| Multiplication | 5 x N = 45 | 9 |
Section 3: Agent Scenario Problems
- 42 + N = 75. N = 33 liters (75 - 42 = 33)
- 150 - 65 = N. N = $85
- 8 x N = 40. N = 5 files (40 ÷ 8 = 5)
Section 4: The Final Code Challenge (Optional)
Step A: X = 32 (4 x 8 = 32) Step B: Z = 18 (32 + Z = 50; 50 - 32 = 18)