Solve: Calculate 5 Flowers × 31 Days Using Daily Pattern Multiplication

To determine the number of flowers Diego plants in 31 days, we employ the following straightforward approach using multiplication:

Given:

• Diego plants $5$ flowers each day.
• We are considering a total span of $31$ days.

The formula to find the total number of flowers Diego plants is:

$\text{Total flowers} = (\text{Flowers per day}) \times (\text{Number of days})$

Substituting the values into the formula, we have:

$\text{Total flowers} = 5 \times 31$

Now, perform the multiplication:

$5 \times 31 = 155$

Therefore, Diego plants a total of $\mathbf{155}$ flowers over a 31-day period.

Checking the answer against the choices, we see that the correct option is choice 2: $155$.