To solve \( 1.8 \times 1.2 \) using partial products, we can break down the numbers into their whole and decimal parts. Here's how it works:
\( 1.8 \) can be broken down into \( 1 + 0.8 \) and \( 1.2 \) can be broken down into \( 1 + 0.2 \).
Now we calculate the partial products:
- \( 1 \times 1 = 1 \)
- \( 1 \times 0.2 = 0.2 \)
- \( 0.8 \times 1 = 0.8 \)
- \( 0.8 \times 0.2 = 0.16 \)
Now add all the partial products together:
\[ 1 + 0.2 + 0.8 + 0.16 = 1 + 0.2 + 0.8 + 0.16 = 2.16 \]
So the correct expression and answer using partial products for \( 1.8 \times 1.2 \) is:
1 + 0.8 + 0.2 + 1.6; 2.16
Thus, this option:
1 + 0.8 + 0.2 + 1.6; 2.16
is the correct choice.