Elementary POW, April 29 - May 3, 1996
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****************************************************** Elementary Problem of the Week, April 29 - May 3, 1996 Two candles are lit at the same time. One is 12 inches tall and burns 1/2 inch per hour and the other is 6 inches tall and burns 1/4 inch per hour. Which candle will burn down first? Explain your answer. ****************************
***************************** Kelsey Peterson, Kelly McKnight Hess Educational Complex, Marianne Blair - Grade 5 Mays Landing, NJ. ***************************** Rachel Forster age 8 grade 3 Cygnet,Tasmania,Australia. Wilkins/Forster family Crooked Tree Point.Cygnet. Tasmania.Australia 7112. ***************************** Kate D., Meghan R., Meghan L., Anna C. Grade 4 Mrs. Galluzzo-Hamilton Bagnall School, Groveland, MA ****************************** Haley, Alan, Allison F., Scott, Jason, Christine, Lindsay, Nisha, Talia, Alexis, Meagan, Jennifer, Andrew, Becky, Alyson C. Grade 6 Mrs. Caruso Bagnall School, Groveland, MA ******************************** Eloise St. Hilda's Western Australia ***************************** Alex and Eric Levenson Mrs. Fisher - grade 5 Aliso School Carpintera **************************** Natalie Stone 3rd grade Friends Select School, Philadelphia ***************************** myoung@csc.sctboces.org ****************************** Kristin 3rd grade ******************************
***************************** Marianne Blair from Hess Educational Complex, Grade 5, 700 Babcock Road, Mays Landing, NJ. As usual this problem caused a lot of discussion. Based on the question as stated, it was agreed that both candles would take the same time to burn down. We did have some of our own questions: Why does one burn faster than the other; and if a candle burns at 1/4" per hour when it it 6", why doesn't the 12" , which burns at 1/2" per hour, slow down to 1/4" per hr when it reaches 6"? Kelsey Peterson: It takes them the same amount of time 24 hours. 24 1/4" = 6 inche candle and the 24 1/2" = 12 inch candle. I found that out by dividing the fraction into whole inches. 12" candle6" candle 1/2= 1 hr.1/4= 1 hr. 1 = 2 hr.2/4= 2 hr. 1-1/2= 3 hr.3/4= 3 hr. 2 = 4 hr.4/4= 4 hr. 2-1/2= 5 hr.5/4= 5 hr. 3= 6 hr.6/4= 6 hr. 3-1/2= 7 hr.7/4= 7 hr. 4= 8 hr.8/4= 8 hr. 4-1/2= 9 hr.9/4= 9 hr. 5=10 hr.10/4= 10 hr. 5-1/2= 11 hr.11/4= 11 hr. 6= 12 hr.12/4= 12 hr. 6-1/2= 13 hr.13/4= 13 hr. 7 = 14 hr.14/4 = 14 hr. 7-1/2=15 hr 8= 16 hr.15/4= 15 hr. 8-1/2 = 17 hr.16/4= 16 hr. 9= 18 hr.17/4= 17 hr. 9-1/2= 19 hr.18/4=18 hr. 10= 20 hr.19/4= 19 hr. 10-1/2= 21 hr.20/4= 20 hr. 11= 22 hr.21/4= 21 hr. 11-1/2= 23 hr.22/4= 22 hr. 12= 24 hr.23/4=23 hr. 24/4= 24 hr. Kelly McKnight: It is the same. I drew two candles. One was 12" and one was 6". I marked the big one every 1/2 inch and the other every 1/4 inch and counted the number of hours. ********************************* >From Rachel Forster age 8 grade 3 Cygnet,Tasmania,Australia. Wilkins/Forster family Crooked Tree Point.Cygnet. Tasmania.Australia 7112. ph.[002] 951456 This is my answer for the elementary problem of the week April 29-May 3. I think that both candles will burn down at the same time. The 12 inch candle burns1/2 inches per hour.There are twenty four 1/2 inches in 12 inches so it will take 24 hours to burn down. The 6 inch candle burns 1/4 inch per hour. There are twenty four 1/4 inches in 6 inches so it will take 24 hours to burn down as well. ******************************** Grade 6 Mrs. Caruso Bagnall School, Groveland, MA Alyson C.: The two candles took the same time to burn down. One way of solving this problem is to draw a picture and solve it from there. Another way is to take a ruler and count the 1/2 inches in 12 inches and 1/4 inches in 6 inches. They are both 24. The way I did it was I multiplied 12 and the denominator of 1/2. Then I multiplied 6 and the denominator of 1/4. They both equal 24. *******************************
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