Explain the difference between dividing in half and dividing by half.

A division in half can yield different results. Take a square for instance, you can divide it in half by cutting along the diagonal, or cutting parallel to the borders.

divide by half. If you are talking about dividing numbers or objects into two equal parts, the expression to use is "divide in half," not "divide by half." Technically, to divide a number by 1/2 is the same as to multiply it by 2