Final answer:
To calculate the amount of water needed when using 10 pounds of flour, multiply the weight of flour by the percentage of water in the formula (70%).
Step-by-step explanation:
To calculate the amount of water needed, we can use the given percentage of water in the formula to find the weight of water. Since the formula specifies that water should be 70% of the weight of flour, we can calculate it as follows:
Water weight = 70% of 10 pounds
Water weight = 0.70 x 10 = 7 pounds
Therefore, 7 pounds of water would be needed when using 10 pounds of flour.