When you multiply by 1 the answer stays the same. 21 × 1 = 21 When you multiply by 10, move all the digits one place to the left, putting a zero in the empty space. 21 × 10 = 210 When you ...

So what fraction of all of the tickets do you have? She bought a quarter of the tickets and you bought a third of those. So you multiply the two numerators together and then multiply the 2 ...