Solve Equations Addition and Subtraction

Use the strip diagram to write an equation. Then solve. Kiki had 17 mystery books. She got some more mystery books as a gift. Now she has a total of 21 mystery books. How many books did Kiki receive as a gift?

• 21 = 17 + p

• 21 + 17 = p

• 4

• 38

Use the strip diagram to write an equation. Then solve.

The pet store had some goldfish. Eight goldfish were sold. There are 28 goldfish left. How many goldfish did the pet store have before some were sold?

• 36

• 28 - 8 = f

• f − 8 = 28

• 20

Use the strip diagram to write an equation. Then solve. Joaquin and Erik worked together on a project. Erik worked 13 hours. Together, they worked 22 hours. How many hours did Joaquin work?

• 9

• 34

• 22 + 12 = h

• 22 = 13 + h

Kierra has 49 pennies in a drawer and some pennies in a jar. She has 81 pennies in all. She represents the number of pennies by using the equation 49 + j = 81. How many pennies does Kierra have in the jar?

Last weekend, Ryan earned $27 babysitting. He earned $19 on Friday and the rest of the money on Saturday. Which equation can you use to find the amount, m, Ryan earned on Saturday?

• m = $27 + $19

• $19 = m + $27

• $27 = m − $19

• m = $27 − $19

Representations Morgan has 28 pieces of jewelry, 10 of which are necklaces. The rest of the jewelry pieces are bracelets. Which equation can you use to find the number of bracelets, b, she has?

• b = 10 – 28

• b = 28 – 10

• 28 = b – 10

• 10 = b + 28

What is the inverse operation needed to solve for p?

594 = p + 600

• subtraction

• addition

• multiplication

• division

Solve for x.

x + 12 = 20

• x = 32

• x = -32

• x = 8

• x = -8

Solve for k.

k - 40 = 260

• 220

• 300

• -300

• -220

Solve for m.

m + 12.7 = 21

• 33.7

• 5.3

• 8.3

• -33.7