4.3.e 4.3.f

Add & Subtract Fractions 4th Grade

Texas Essential Knowledge and Skills (TEKS): 4.3.e
represent and solve addition and subtraction of fractions with equal denominators using objects and pictorial models that build to the number line and properties of operations;
Texas Essential Knowledge and Skills (TEKS): 4.3.f
evaluate the reasonableness of sums and differences of fractions using benchmark fractions 0, 1/4, 1/2, 3/4, and 1, referring to the same whole; and

A fraction can be modeled by a whole divided into equal parts.
The sum of two fractions can be represented using fraction models.

\frac{1}{8}

can be represented by a grid divided into eight equal parts with one part shaded.

\frac{2}{8}

can be represented by a grid divided into eight equal parts with two parts shaded.

\frac{3}{8}

can be represented by a grid divided into eight equal parts with three parts shaded.

A fraction can be modeled by a whole divided into equal parts.
The difference of two fractions can be represented using fraction models.

\frac{3}{5}

can be represented by a fraction strip divided into five equal parts with three parts shaded.

\frac{1}{5}

can be represented by a fraction strip divided into five equal parts with one part shaded.

\frac{2}{5}

can be represented by a fraction strip divided into five equal parts with two parts shaded.

To add fractions with like denominators, add the
numerators and keep the denominator the same.

$\frac{2}{6}$	$+$	$\frac{3}{6}$	$=$	$?$
	$+$		$=$	$?$

$\frac{2}{6}$	$+$	$\frac{3}{6}$	$=$	$\frac{5}{6}$
	$+$		$=$

To subtract fractions with like denominators, subtract the
numerators and keep the denominator the same.

$\frac{7}{10}$	$-$	$\frac{4}{10}$	$=$	$?$
	$-$		$=$	$?$

$\frac{7}{10}$	$-$	$\frac{4}{10}$	$=$	$\frac{3}{10}$
	$-$		$=$

Benchmarks can be used to estimate the sum or difference of fractions.

Benchmarks are fractions that are easier to
add or subtract, like

0, \frac{1}{4}, \frac{1}{2}, \frac{3}{4},

and

1

\frac{1}{12}

can be estimated as

0

\frac{8}{11}

can be estimated as

\frac{3}{4}

So, the sum is closer to

\frac{3}{4}

than

0

Add & Subtract Fractions