
Version 13, changed by LFS. 02/13/2007. Show version history
| 2. Fractions* | ![]() |
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2.1 Writing & Thinking about Fractions: (Review)
2.1.1 Understands different interpretations of fractions, for example, parts of a whole, parts of a set, and division of whole numbers by whole numbers. Understands that purpose of the denominator is to name the size of the part (a denominator of 2 – means halves, a denominator of 3 means thirds,…) and the numerator tells the number of those parts we have (3/4 - means 3 fourths,…).
2.1.2 Converts improper fractions to mixed numbers and vice versa. Understands that mixed numbers are used only to estimate the size of a fraction.
2.2 Comparing and Ordering Fractions*: (Review)
Compares and orders positive and negative fractions. Understands the comparative order of two fractions with the same denominator and different numerators and vice-versa.
2.3 Simplifying Fractions*: (Emphasis)
Understands the principles of cancellation, finds common factors and simplifies fractions.
2.4 Adding & Subtracting Fractions with Like Denominators*: (Review)
Understands that denominators do not “add”, i.e. that the statement 2/5+1/5=3/5 is read and means: ‘2 fifths + 1 fifth = 3 fifths’.
2.5 Adding & Subtracting Fractions with Unlike Denominators: (Review)
Can find the greatest common factor and then the least common multiple of two numbers. Understands how to convert fractions with unlike denominators to fractions with like denominators and then add or subtract as required.
2.6 Multiplying & Dividing Fractions*: (Review)
Understand the concept of multiplication and division of fractions and how to invert and multiply when dividing. Understands how to solve double fractions and the importance of the position of the main fraction line, i.e. (3/5)/23/(5/2).
2.7 Problem Solving with Fractions: (Review)
Add, subtracts, multiplies and divides fractions to solve problems..
*Crucial Review Skills:
Ordering Fractions: Understands that for positive fractions a/b<c/d if ad<bc.
Simplifying Fractions: Understands the ideas of expansion, contraction and cancellation of fractions:
e.g.
and
.
Dividing Fractions: Understands that the rule ‘invert and multiply’ is not a special (magic) rule when dividing fractions,
but that we always invert and multiply when dividing. That is,
. (See also Ed2Ed.)