Which calculation method estimates the number of 8 x 8 x 16 concrete blocks needed for a wall?

To determine the number of 8 x 8 x 16 concrete blocks needed for a wall, the correct calculation method involves understanding the area that each block covers and how many of those blocks fit into the total wall area. The option that states to divide the square footage of the face area by 100 and then multiply by 112.5 effectively provides a method to account for the size of the blocks while including allowances for mortar joint space between the blocks.

Each standard 8 x 8 x 16 concrete block has a face area of approximately 1.125 square feet (since the calculated area is 8 inches by 16 inches, resulting in an area of 1.33 square feet before considering the mortar). Therefore, accommodating a typical mortar joint leads to the calculation where dividing by 100 helps to convert a larger area measurement into a manageable calculation unit, while multiplying by 112.5 helps to estimate the number of blocks needed over a standard area effectively based on real-world building practices.

This method incorporates the overall wall dimensions while accurately estimating the number of blocks needed, considering the size of each block and the gaps for mortar, making it a practical and straightforward approach to estimating block quantities for construction purposes.