# Problem
Fill in the blank with the correct decimal value to do a multiply by 16: `LSL r0, __`.
# Process
The `LSL` instruction moves the bits in a binary value from right to left and inserts zeroes at the right of the number for however many bits were shifted. Since binary is a base-2 number system, each position in a binary number represents a power of 2. Just like how moving a digit in a decimal number from the right to the left multiplies its value by 10, moving a binary digit from the right to the left multiplies its value by 2. So, the question is essentially asking what power of 2 equals 16. Since it looks like we're filling in an immediate value, we also have to make sure we include the correct syntax.
$\log_216=4$
# Answer
```
#4
```