Solving multiplication problem sums

Even though sonshine boy can do multiplication, I wanted to make sure he truly, fully understand what it's all about. The best way, at least to me, is to give him a problem sum on multiplication to solve. Hence, I've been verbally throwing him a number of sums to solve. For instance, I'd ask him; if there are 3 fishballs in 1 stick and mummy buys 3 sticks, how many fishballs are there? Or I could ask if there are 9 sweets in 1 packet, mummy buys 4 packets how many sweets in all? Even though he can spew out the correct answers, I'd insist that he gives me the equation. Sometimes he'd get it mix up I.e 3x4 instead of 4x3, such cases I'd correct him. After a few rounds, he now knows how to solve a multiplication problem sum.