To determine the length of each smaller piece of yarn when a piece of yarn that is 19.2 units long is cut into four equal pieces, you need to divide the total length of the yarn by the number of pieces.
The mathematical expression to use for this situation is:
\[ \text{Length of each piece} = \frac{\text{Total length of yarn}}{\text{Number of pieces}} = \frac{19.2}{4} \]
Now let's evaluate the options you provided:
- A: \( 19.2 * 4 \) – This would give the total length if you multiplied instead of divided.
- B: \( 19.2 - 4 \) – This would subtract 4 from the total length and is not correct.
- C: \( 19.2 / 4 \) – This divides the total length by the number of pieces, which is correct.
- D: \( 19.2 + 4 \) – This would add 4 to the total length, which is not correct.
Therefore, the correct expression that represents the length of each smaller piece of yarn is:
C: 19.2 / 4.
Now, performing the calculation:
\[ 19.2 \div 4 = 4.8 \]
So, each smaller piece of yarn is 4.8 units long.