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Example1

Title: Decimal Equivalent Fraction

Grade Lesson s2-l3

Explanation: The best way to understand SAT-4 is by looking at some examples. Take turns and read each example for easy understanding.

Examples

Topics → Definition Example1

Solve the expression \$3/8 - 4/5 + 6/9\$.

Step: 1

First, deal with the fractions by finding a common denominator. The fractions are:
\$3/8 - 4/5 + 6/9\$
To add or subtract fractions, need a common denominator. The denominators are 8, 5, and 9. The least common denominator of 8, 5, and 9 is 360.

$1a$

. https://uat-image.saibook.org/edu/math/psat/v4/psat-core/s2/l3/example1/1a.jpg

Explanation:

First, find a common denominator for the fractions \$3/8, 4/5, 6/9\$. The denominators are 8, 5, and 9. Their least common Multiplie (LCM) is 360.

Step: 2

Now, convert each fraction to have the denominator 360:

\$3/8 = (3 times 45)/(8 times 45)\$ = \$135/360\$

\$4/5 = (4 times 72)/(5 times 72)\$ = \$288/360\$

\$6/9 = (6 times 40)/(9 times 40)\$ = \$240/360\$

$2a$

. https://uat-image.saibook.org/edu/math/psat/v4/psat-core/s2/l3/example1/2a.jpg

Explanation:

Convert each fraction to have a denominator of 360.

Step: 3

Now that we have a common denominator, we can add and subtract the numerators:
\$135/360 - 288/360 + 240/360\$

$3a$

. https://uat-image.saibook.org/edu/math/psat/v4/psat-core/s2/l3/example1/3a.jpg

Explanation:

Now that the fractions have the same denominator, we can combine the numerators: \$135/360, 288/360, 240/360\$.

Step: 4

First subtract, 135 - 288 = -153
Then add, -153 + 240 = 87
So, the expression simplifies to: \$87/360\$.

$4a$

. https://uat-image.saibook.org/edu/math/psat/v4/psat-core/s2/l3/example1/4a.jpg

Explanation:

First, subtract: 135 - 288 = -153. Then, add: 153 + 240 = 87. So, the expression simplifies to: \$87/360\$.

Step: 5

Simplify \$87/360\$, find the greatest common divisor (GCD) of 87 and 360. The GCD of 87 and 360 is 3.

Now, divide both the numerator and denominator by 3:
\$87/360 \div 3/3 = 29/120\$ = 0.241.

$5a$

. https://uat-image.saibook.org/edu/math/psat/v4/psat-core/s2/l3/example1/5a.jpg

Explanation:

Simplify, \$87/360\$ by finding the greatest common divisor (GCD) of 87 and 360, which is 3. Divide both the numerator and denominator by 3: \$29/120 = 0.241\$.