Question

Using lattice multiplication, find the total cost of all the books.

• A. $19,306
• B. $18,206
• C. $19,206
• D. $18,306

Answer 1

The correct option is A $19,306

Number of books in the rack = 197
$\text{Cost of 1 book}=\$98$

$\text{∴ Total cost of all books}=197\times \$98$

Solving by lattice multiplication:

Step 1: Draw a 3x2 table and on top and right, just put the digits:


Step 2: Draw the diagonals and write the digits in the boxes:


Step 3: Add the digits along the diagonal and write them from the left side to the right side:


So, the total cost of all books = $19,306