Upper Primary Mathematics Fractions - Commonwealth of Learning

Answers for Self Assessment
1. Addition of common fractions using set models. Danny has one and a
half packets of chocolate beads. His sister gives him five-sixth of a packet
of chocolate beads. How many packets does he have altogether?
=
1 +
3
+
6
14
6
or
2
1
3
Combine
shaded beads.
These are all
in sets of six.
2. “Fractions spokes”
The number of circles is one less the lowest common denominator. In this
puzzle, the number of circles is 7. Therefore, the lowest common
7
denominator is 8. In this situation the greatest proper fraction is and
8
1
1 2 3
the unit fraction is . The fractions in an ordered manner are , , ,
8
8 8 8
4 5 6 7
, , , . Put the smallest fraction in the centre. Then fill the outside
8 8 8 8
circle by pairing two fractions and putting them in the two circles which
are diagonal. Pair the greatest fraction with the next smallest fraction and
so on. Convert all fractions to their simplest form before putting them in
the circle.
7 3
8 4
1
2
3
8
1
8
3. (i) Boyd has three-quarters of a metre of cloth. When he comes back
from school he finds only two-thirds of a metre of cloth. How much
cloth is missing?
(ii) Boyd has three-quarters of a metre of cloth. He gives away twothirds
of a metre to Carol. How much cloth is left?
(iii) Boyd has three-quarters of a metre of cloth. Ellen has two-thirds of a
metre of cloth. How much longer is Boyd’s cloth than Ellen’s cloth?
4. Lovemore is always thinking in base ten. When he renamed one instead
of using the denominator (6) to get the equivalent fraction, Lovemore
10
6
uses base ten place value. As such, 1 = instead of 1 = .
6
6
This pupil can be helped by re-introducing the concept of changing mixed
numbers to improper fractions using models.
Module 2: Unit 2 24 Addition and Subtraction of Common Fractions
1
4
5
8
5
6