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## 5th grade foundations (Eureka Math/EngageNY)

# Comparing with multiplication: age

Sal solves a multiplication comparison word problem. Created by Sal Khan and Monterey Institute for Technology and Education.

## Video transcript

We're told that Jared is twice
the age of his brother, Peter. So Jared is twice the age
of his brother, Peter. Peter is 4 years old. And Jared is twice the
age of his brother, Peter. So Jared is twice
Peter's age of 4. And then they tell us, Talia's
age is 3 times Jared's age. How old are Talia and Jared? So Talia's age is 3
times Jared's age. So let's write this down. We have Peter is 4 years old. So Peter's age,
he's 4 years old. Jared is twice the age
of his brother, Peter. Let me do that in yellow. That's not yellow. Jared is twice the
age of his brother. Twice is the same thing as 2
times the age of his brother. You could say Jared is
twice the age of his brother or Jared is 2 times
the age of his brother. Well, his brother is 4. They told us that
right over there. So Jared is going to
be 2 times 4 years old. And if you know your
multiplication tables, you know that's the
same thing as 8. 2 times 4 is 8. 4 times 2 is 8. Or you know this is the
same thing as Peter's age twice, which is the
same thing as 4 plus 4. That would also get you 8. So Jared's age is equal to 8. And then, finally, they
say Talia's age-- so let me write Talia
right over here. Talia's age and they tell
it to us right over here. It's 3 times Jared's age. So Talia's age is 3
times Jared's age. Well, we were able to
figure out Jared's age. It is 8. It is 3 times Jared's age. If you know your
multiplication tables, this should maybe
jump out at you. And your multiplication tables
really are one of those things in mathematics that you should
really just know back and forth just because it will make
the rest of your life very, very, very simple. Or you could view 3 times 8
as literally 8 three times. So it's 8 plus 8 plus 8. 8 plus 8 is 16, 16 plus 8 is 24. So 3 times 8 is 24. So Peter is 4, Jared
is 8, and Talia is 24.