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.
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- so at (0:19) twice as much means multiply the age or halve it(8 votes)
- 'Twice as much' basically means 2 times something, which means you multiply the age by 2.(3 votes)
- is comparing age all the time subtractio, divison or multiplacation?(3 votes)
- i'd say "most of the time" not" some of the time." get the facts of it.(3 votes)
- This is so easy... Why is it in 4th grade section for math?(4 votes)
- I don't know. Maybe it's for students who weren't taught it earlier? Sometimes topics and videos on Khan Academy seem to be put in the wrong places.(3 votes)
- does using letters in math really make word problems easier?(3 votes)
- Yes, using variables can make problems more clearer to solve and easier to understand.(4 votes)
- so jared is definitely 8, right?(3 votes)
- Yes, he is! Great job figuring it out :)(4 votes)
- Did that video have to 2 muintes and 38 seconds?(4 votes)
- how did he get black thing(4 votes)
- Do you do twice as many,it means multiple(3 votes)
- how do you get to do the Work
wAtch the video(3 votes)
- i don't get it let me look again or watch again(3 votes)
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.