Favorite Pets
(page 152)

(January 2011) Here are solutions from the prolific class of fifth-graders at Hale Kula Elementary in Wahiawa, Hawaii.

The question I was trying to answer was what fraction of the kids preferred potbellied pigs? The first clue stated that fifteen kids answered the favorite pet survey at Pets Galore in the Allendale Mall. They had four choices that were: turtle, pot-bellied pig, capybara, and cockatiel. Another clue said that 20% of the kids preferred turtles. I know that 20% of 15 is 5 so 5 kids preferred turtles. The next clue said that 120% of the kids preferred capybara and 6 times as many kids preferred capybara than cockatiels. To solve 120% of 15 I multiplied 1.20 by 5 and got 1. That tells me that 1 person preferred cockatiels and 6 people preferred capybaras because 1 multiplied by 6 equals 6. After that clue I could solve how many kids preferred potbellied pigs because if you add 5+6+1 it equals 12 and there are 3 left so 3 kids preferred potbellied pigs. Finally I have to change everything into a fraction, 1/3 preferred turtles, 6/15 preferred capybaras, 1/15 preferred cockatiels, and 1/5 preferred potbellied pigs.


The answer is 3/15 b/c there is 15 kids and clue #4 says "One-third of the kids preferred turtles." So one-third of 15 is 5 so I have 10 kids left that like something.Clue #5 says "The number of kids who preferred capybaras was 120% of the number who preferred turtles." 120% of the turtles is 6 so I have 4 kids left that like something. Clue #2. The number of kids who preferred cockatiels was 20% of the number who preferred turtles. So 20% of 5 is 1 so the number of people that liked cockatiels is 1, 5+6+1=12, so the number of people that like the pot-bellied pig is 3 people.


how i figured the question was i looked at the easiest clue witch was 15 kids took the survey. then i took the rest of the clues looked like this.

  • turtles = 1/3 or 5
  • cockateils = 20% of turtles =1
  • Capybara = 120% of turtles = 6

then when you get the others you can add them up and get the potbellied pigs. 5 1 +6 ----- 12

then you can get the rest witch is three because 12 +3 ---- 15

then you get your answer

(hint) when you see OF like when it says 120% OF turtles it means that you multiply!

Here we have a solution to Favorite Pets from some 6th graders: Chrissy, Dajouna, Thurmeka, and Antoine at the Madison Ave. Baptist Academy in Paterson, NJ.

Solution:

Fifteen (15) kids had to choose between pot-bellied pigs, capybaras, cocatiels and turtles. First, we figured out what the percentages were as fractions. 20% is 1/5; 120% is 1 1/5 (100% is equal to 1 and 20% is equal to 1/5. 1 + 1/5 = 1 1/5).

1/3 of the children liked turtles. So, we had 1/3 and we multiplied it by 15 and got 5. Then, since 120% of the kids who liked turtles liked capybaras, we multiplied 1/3 by 1 1/5 and we got 2/5, which is the fraction of the students who preferred capybaras. 20% of the number of students who liked turtles liked cockatiels. So, we multiplied 1/3 by 1/5 and we got 1/15.

We added 2/5, 1/15, and 1/3 and we got 12/15. We subtracted 12/15 (the students counted so far) from 15/15 (all the students) and got 3/15 and reduced it to 1/5. 1/5 is the fraction of the students who preferred pot-bellied kids.

Okay, notice how these kids changed the percentages to fractions so they worked just with one or the other. Good idea. Also, notice when (at the end of the second paragraph) they multiuplied two fractions together. Does that make sense?

Only one obvious problem, and that's a curious typo at the very end!!

You know, you can answer these questions too! Just write to

back to the Answer Book page