Explanation
To calculate how many \(2 \times 2\) squares will fit first find the area of the larger rectangle. Area for a rectangle is height multiplied by width: \(20 \times 10 = 200\). A single \(2 \times 2\)square has an area of \(2 \times 2 = 4\) so to find the number of these squares that will fit in the large rectangle divide the rectangle's area by the square's area: \(200 \div 4 = 50\)