Can you explain how these tricks work?
Can you make up you own similar trick?
For a real challenge – can you use algebra to explain how these tricks work?
Try each set of instructions at least two or three times with different numbers. Notice what answer you get each time.
| 1. | Think of a number | ||
| 2. | Add 4 to it | Add 7 to it | Add 5 to it |
| 3. | Double the result | Multiply the answer by 3 | Multiply the answer by 4 |
| 4. | Take away 6 | Subtract 9 | Subtract 8 |
| 5. | Halve the result | Divide the answer by 3 | Divide the answer by 4 |
| 6. | Subtract the number you first thought of | ||
| 7. | WHAT DO YOU GET? | ||
| 8. | Now try again with other numbers and see what you get | ||
