Emma seys that the preduct of a 3-digit number and a 1-digit number will be either a 3 digit number or a 4 digit number. Does Emma's statement make sense

It does make sense because a three digit number like 565 plus a one digit number like 5 would only equal 570, but a three digit number like 991 plus a one digit number such as 9 would be 1000, a four digit number