Multiplying by Repeated Addition

The result of multiplication is the total number (product) that would be obtained by combining several (multiplier) groups of similar size (multiplicand). The same result can be obtained by repeated addition. If we are combining 7 groups with 4 objects in each group, we could arrive at the same answer by addition. For example, 4+4+4+4+4+4+4=28 is equivalent to the multiplication equation 7*4=28.

Write the corresponding multiplication expression.