Treasure Hunting Fractions A tale of 3 greedy pirates who didn’t know much about fractions. Rebekah Manson
Multiplying Fractions• Listen to “A Fair Share” – which treasure hunter ends up with the greatest share?
• Three brave, but not very bright, treasure hunters recovered a small box of priceless Spanish doubloons aboard a sunken ship. They took the coins back to their campsite. Since it was late, they decided to go to sleep and divide the treasure the next day.• One of the treasure hunters, fearing that the others did not understand mathematics well enough to give out fair shares, took 1/3 of the coins in the middle of the night and fled into the darkness.• Later that night, another treasure hunter awoke and saw that some of the coins were missing. That treasure hunter took 1/3 of the remaining coins and also fled into the night.• The third treasure hunter awoke and was surprised to see the others gone and many of the coins missing. Trusting that the others left a fair share, the third treasure hunter took the remaining coins and walked away whistling happily.• Which of the treasure hunters ended up with the greatest share of the doubloons?
1/3 of 2/3 = 1/3 * 2/3=
2/3 of 2/3 = 2/3 * 2/3 =
Summary• “Of” means multiply• 1st pirate 1/3 of 3/3 = 3/9• 2nd pirate 1/3 of 2/3 = 2/9• 3rd pirate 2/3 of 2/3 = 4/9• Therefore the 3rd pirate walked away with the most Spanish Doubloons!
• Rules for multiplying fractions/mixed numbers – Change each number into fraction form (may be improper) • To change a whole number to a fraction place it over 1 • 3= – Multiply numerators – Multiply denominator – Simplify (reduce)
Arrg, time for some practice mateys!• 1/3 x 5/6• 3/5 of 30• 4 x 4/5• 2/3 x 2 1/12• 3/5 of the 6th grade will be taking Spanish next year. If there are 130 6th graders, how many will take Spanish next year?
Now it be ye turn mateys!• 5/7 x 2/3• 2 ¾ x 1 1/6• 1/6 of 4• 4/3 x 2/9• 3 of 3/7