Rational Numbers Review (Word Problems)

Rational Numbers Review (Word Problems)

Aim: How can we solve word problems with rational numbers?

We know that any subtraction can be turned into addition through KCC

-8 - 2 = -8 + (-2)

-10

In word problems we can identify positive words and negative words but remember that the negative word represents either "subtraction" OR "a negative number"

Jaileen was 7 feet below sea level and then dove down 4 more feet. What is Jaileen's current elevation?

-7 - 4 = -7 + (-4)=

-11 feet

Multiple Select

Aolani overdrew her checking account by $10. She later wrote a check for $40. What does her bank account look like now? Check all that apply

• 10 - 40 = -30

• -10 - 40 = -50

• 10 + (-40) = -30

• -10 + (-40) = -50

Multiple Select

Daniel had $85. Later that day he withdrew $15. How much money does Daniel now have? Check all that apply

• -85 - 15 = -100

• 85 - 15 = 70

• 85 + (-15) = 70

• -85 + (-15) = -100

Multiple Choice

Cristian gained 5 yards on when playing football. On the next down he got a penalty and lost 10 yards. How many yards does he have?

• -5 + (-10) = -15 yards

• -5 + 10 = 5 yards

• 5 + (-10) = -5 yards

• 5 + 10 = 15 yards

The only time you subtract a negative in a word problem is if it say "find the difference" or "find the change" or "is getting rid of a debt"

Eduardo is 7 meters above sea level. He dives down into the ocean and lands 3 meters below sea level. What is the difference of his elevations?

7 - (-3) = 7 + 3 =

10

Multiple Choice

It was 50 degrees at noon but then dropped to 12 degrees below zero at midnight. What is the difference in temperature from noon to midnight?

• 50 - (-12) = 50 + 12 = 62

• 50 - 12 = 50 + (-12) = 38

• -50 - 12 = -50 + (-12) = -62

• -50 - (-12) = -50 + 12 = -38

Multiple Choice

Jeremiah goes skydiving into the lake! He starts 100 meters above sea-level and then lands 10 meters below sea-level. What is the change in his elevation?

• 100 - 10 =90

• 100 - (-10)= 110

• -100 - 10 = -110

• -100 - (-10) = -90

Multiple Choice

Daniel was $30 in debt but was able to pay off $15 of his debt. What does his money situation look like now?

• 30 - 15 = 15

• - 30 - 15 = -30 + (-15) = -45

• -30 - (-15) =-30 +15 = -15

• 30 + 15 = 45

Converting a fraction into a decimal

• Divide the numerator by the denominator

•  $\frac{3}{4}=3\div4=0.75$  

Tonight you have a mixed review for HW!