Operations with Rational Numbers

Operations with Rational Numbers

by Kasey Renshaw

DECIMALS​

​

​ADDING AND SUBTRACTING DECIMALS

• ​LINE UP YOUR DECIMALS

Multiple Choice

7.32 + (-180.6)

• -183.32

• 173.28

• -173.28

• -187.92

Multiple Choice

4.65 - (-32.5)

• -37.15

• 27.85

• 37.15

• -27.85

​MUTLIPLYING DECIMALS

• ​IGNORE THE DECIMALS

• ​THEN, COUNT THE DECIMALS TO THE RIGHT OF EACH FACTOR

Multiple Choice

$$-4.6\times\left(-2.73\right)$$  

• 12.558

• -12.558

• -12.5580

• 12.5580

​DIVIDING DECIMALS

• YOUR DIVISOR CANNOT BE A DECIMMAL​

• ​IF YOU MOVE THE DECIMAL IN THE DIVISOR, YOU MUST MOVE THE DECIMAL IN THE DIVIDEND THE SAME NUMBER OF PLACES

Multiple Choice

$$-37.5\div2.5$$  

• -0.15

• -1.5

• -15

• -150

​FRACTIONS

​

​ADDING AND SUBTRACTING FRACTIONS

• YOU MUST HAVE THE SAME DENOMINATOR​

Multiple Choice

$$-\frac{5}{6}+\left(-\frac{4}{9}\right)$$  

• $$-1\frac{5}{18}$$  

• $$1\frac{5}{18}$$  

• $$-\frac{23}{18}$$  

• $$-\frac{9}{15}$$  

Multiple Choice

$$-\frac{3}{7}-\left(-\frac{5}{14}\right)$$  

• $$\frac{11}{14}$$  

• $$-\frac{11}{14}$$  

• $$\frac{1}{14}$$  

• $$-\frac{1}{14}$$  

​MULTIPLYING FRACTIONS

• ​JUST MULTIPLY ACROSS

• ​YOU DO NOT NEED TO HAVE COMMON DENOMINATORS

Multiple Choice

$$-\frac{3}{5}\times\left(-\frac{7}{6}\right)$$  

• $$\frac{21}{30}$$  

• $$-\frac{7}{10}$$  

• $$\frac{7}{10}$$  

• $$-\frac{21}{30}$$  

Multiple Choice

$$-1\frac{3}{5}\times3\frac{2}{6}$$  

• $$-5\frac{1}{3}$$  

• $$5\frac{1}{3}$$  

• $$-5\frac{5}{15}$$  

• $$5\frac{5}{15}$$  

​DIVIDING FRACTIONS

• ​KCF (KEEP, CHANGE, FLIP)

• ​CHANGE DIVISION TO MULTIPLICATION

• ​FLIP THE SECOND FRACTION TO ITS RECIPROCAL

Multiple Choice

$$4\frac{1}{3}\div\left(-\frac{1}{2}\right)$$  

• $$2\frac{1}{6}$$  

• $$-2\frac{1}{6}$$  

• $$-8\frac{2}{3}$$  

• $$8\frac{2}{3}$$