7th Grade Math

Decomposing #s

100

Decompose −8.65 into its integer part and non-integer part.

-8 + (-0.65)

200

Rewrite −5.4 + 2.4 using additive inverses to make the sum easier to find.

−3 + (−2.4) + 2.4 = −3

300

Decompose −6 3/4 into an integer and a fractional part.

-6 + (-3/4)

400

Use decomposition to evaluate −7.8 + (−4.65).

-12.45

500

Use additive inverses or decomposition to evaluate −12.75 + 8.4 + (−3.25).

-7.6

Rational Number Addition

100

Evaluate −8.5 + 3.75

-4.75

200

Evaluate −6.35 + (−4.85)

-11.2

300

Evaluate −3/4 + 5/6.

1/12

400

Evaluate −4 2/3 + 2 5/6.

_{-1 5/6}

500

Evaluate −7 3/8 + (−2 5/6).

-10 5/24

Subtraction Challenge

100

Evaluate 9 - (-7)

16

200

Evaluate -12 - 8

-20

300

Evaluate −6 − (−15).

9

400

Evaluate −4.75 − (−9.6).

4.85

500

Evaluate −8 1/4 − (−3 5/6).

-4 5/12

Unknown Addends

100

Find the unknown addend: 8 + ___ = −3

-11

200

Find the unknown addend: −9 + ___ = 7.

16

300

Rewrite −6 − 11 as an unknown addend equation and solve.

11 + __ =-6 ; -17

400

Rewrite −4 − (−13) as an unknown addend equation and solve.

_{-13 + __= -4 ; 9}

500

Find x: −7.25 + x = 5.5. Explain the direction of movement on a number line.

x = 12.75; move 12.75 units right 

Math Brain Busters

100

What is the distance between −8 and 13 on a number line?

21

200

A temperature of −12.5°F rises 18.75°F. What is the new temperature?

6.25 degrees

300

A submarine is at −35.5 feet. It descends 18.75 feet. What is its new position?

_{-52.25 ft}

400

A temperature starts at −8.5°F, rises 13.75°F, then drops 9.5°F. What is the final temperature?

-4.25 ft

500

A bank account starts at −$18.75. You deposit $32.50 and withdraw $21.85. What is the balance?

-$8.10