Name __________________________
MTH 2620: Lesson 3, Extra Practice Solutions
1. Suppose the following set of 21 check marks represents
!
!
!
!
!
.
How many check marks would represent !?
=
!!
!
!
!
!
!
!!
= !!
=
The quantity represented with ! is the same as
3/8 and then another ½/8. Or, we could think of
!!
!
!
=
!!
!
!
=
!!
!
!
=
!!
!
!
=
!!
!
!
!
!
it as ! which is made up of 7 equal pieces that
are ½/8. So, 21 check marks divided into 7
equal parts shows that 3 check marks is equal to
½ /8. Therefore, 1/8 is 6 check marks and 5/8
would be 5 x 6 = 30 check marks.
2. Suppose the following set of 48 Xs represents
!
!
!
!
!"
.
How many Xs would represent ? Explain your reasoning.
!
1!
5 X X
28 X X
X X
X X
X X
X X
X X
X X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
!
!
!
=
!"
!"
!
!"
which means that the 48 Xs represents 12
copies of
!
!
!"
. So, if I split the 48 Xs into 12 equal
parts, I see that each part will equal
respresent
!
!
!"
!
!
!"
. So, 4 Xs
.
We need 5 copies of
!
!
!
!"
to get
!
!
!"
!
= !". So, 5 x 4 = 20
Xs represents !" .
!
Then, we need 28 copies of !" to represent a BMU. So,
28 x 20 = 560 Xs represent the BMU.
Therefore, ½ will be represented by ½ of 560 Xs
= 280 Xs.