Yadira's mom is buying hot dogs and hot dog buns for the family barbecue. Hot dogs come in packs of 12 and hot dog buns come in packs of 9. The store does not sell parts of a pack and Yadira's mom wants the same number of hot dogs as hot dog buns. What is the smallest total number of hot dogs that Yadira's mom can purchase?
You start multiplying 9 times a number and 12 times a number until the product is the same for both. If you multiply 9x4 you get 36. If you multiply 12x3 you get 36 too. That's how you get both numbers the same