Natalie gp
gallegon 61
a story of ratios
lesson 6
6.1
lesson summary
when solving problems in which a ratio between two quantities changes, it is to draw a before tape diagram
and an after tape diagram.
problem set
1.
shelley compared the number of oak trees to the number of maple trees as part of a study about hardwood trees in
a woodlot. she counted 9 maple trees to every 5 oak trees. later in the year there was a bug problem and many
trees died. new trees were planted to make sure there was the same number of trees as before the bug problem.
the new ratio of the number of maple trees to the number of oak trees is 3: 11. after planting new trees, there
were 132 oak trees. how many more maple trees were in the woodlot before the bug problem than after the bug
problem? explain.
2. the school band is comprised of middle school students and high school students, but it always has the same
maximum capacity. last year the ratio of the number of middle school students to the number of high school
students was 1: 8. however, this year the ratio of the number of middle school students to the number of high
school students changed to 2: 7. if there are 18 middle school students in the band this year, how many fewer high
school students are in the band this year compared to last year? explain.
mio a 659
wood lot
iii
mo 3: 11
givin: 132