The product of two factors in fourth grade mathematics is 75. If one factor is multiplied by 7 and the other factor is divided by 7, what is the product?

Solution: The multiplication of two factors is 75. These two factor series formulas do not include multiplicative commutative law and decimal form. There are three formulations.

That is, 1x75=75, 3x25=75, 5x 15=75.

Among these three formulas, there are six forms of multiplying one factor by seven and dividing the other factor by seven, but the product is still 75. The formula is as follows:

1x7ⅹ75÷7

=7x75÷7

=75x7÷7 (the first two factors can be exchanged).

=75x(7÷7) (parentheses are added after the multiplication sign, and the division sign remains unchanged).

=75x 1

=75

1÷7x75x7

= 1/7x75ⅹ7 (write division as fraction)

=( 1/7x7)ⅹ75 (multiplicative associative law)

= 1x75=75

Try the following four formulas yourself:

3ⅹ7x25÷7