Solve and Write Addition and Subtraction Equations

3 + x = 19

What is the first step?

• Add 3 to both sides

• Subtract 3 from both sides

• Multiply by 3 on both sides

• Divide by 3 on both sides

7.8 = 3.5 + a

• 11.3

• 4.3

• 10.3

• 5.3

Marcela is saving money to go to an amusement park. One ticket costs a total of $240 and Marcela has already saved $125. Write and solve equation which represent the amount of money she still needs to save.

• x - 125 = 240

  She still needs to save $365

• 125 + x = 240

  She still needs to save $365

• 125 + x = 240

  She still needs to save $115

• x - 125 = 240

  She still needs to save $115.

In Ms. C's 2nd Period math class, there are a total of 12 girls. This is 3 fewer than the number of girls in Ms. C's 3rd Period class. Write and solve an equation that represents the number of girls in the 3rd Period math class.

On a recent quiz, Kat earned 13 more points than Jimmy. Kat earned a total of 84 points on her quiz. How many points did Jimmy earn?

Write an equation that represents the number of points Jimmy earned on his quiz. Use j to represent Jimmy's points in your equation.

A stadium has a total of  18,000 seats.  Of these, 7,500 are field seats, and the rest are grandstand seats.  Write an equation that could be used to find the number of grandstand seats s. 

• 18,000 + 7,500 = s

• s + 7,500 = 18,000

• 7,500 - s = 18,000

• 7,500 - 18,000 = s

¼ + b = ¾

• 1

• ½

What can I do to the hanger to get the x by itself and keep the hanger balanced?

• add 3 to both sides

• subtract 8 from both sides

• add 8 to both sides

• subtract 3 from both sides

What is the correct step to solve for the variable?
15 = m - 5

• add 5 to both sides

• add 15 to both sides

• subtract 15 from both sides

• subtract 5 from both sides

Write and solve the equation: You have a stack with some baseball cards. You gave 21 cards to a friend and you now have 9 left over. How many cards(c) did you start with?

• c + 9 = 21 ; c = 12

• c - 9 = 21 ; c = 30

• c - 21 = 9 ; c = 30

• c + 21 = 9 ; c = -12