Question

How can I multiply 306x21 using standard algorithm?

Answer 1

To multiply 306 by 21 using the standard algorithm, follow these steps:

1. **Write the numbers vertically**:
```
306
× 21
──────
```

2. **Multiply the bottom number's units place (1) by the top number (306)**:
- 1 × 306 = 306
- Write this result below the line:
```
306
× 21
──────
306 (this is 306 × 1)
```

3. **Multiply the bottom number's tens place (2) by the top number (306)**:
- 2 × 306 = 612
- Since you are in the tens place, put a zero in the units place of this result (essentially, you are multiplying by 20):
- Write this result below the previous line, shifted one position to the left:
```
306
× 21
──────
306 (this is 306 × 1)
+6120 (this is 306 × 20)
```

4. **Add the two results**:
```
306
+ 6120
──────
6426
```

5. **Final answer**:
Therefore, \( 306 × 21 = 6426 \).