2½ × 1⅓
Today we'll multiply two mixed numbers: two and a half times one and a third.
Let's estimate first. Two and a half rounds to three, and one and a third is close to one. So our answer should land near three.
First, change two and a half into an improper fraction. Two times two is four, plus one is five — that's five halves.
Next, one and a third becomes four thirds. One times three is three, plus one is four.
Now we multiply five halves times four thirds.
Multiply the top numbers: five times four is twenty.
Multiply the bottom numbers: two times three is six.
Twenty sixths can be simplified. Divide both numbers by two to get ten thirds.
Now turn ten thirds back into a mixed number. Three fits into ten three times, with one left over — three and one third.
Three and one third is close to our estimate of three. That checks out!
Two and a half times one and a third is three and one third.