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Cogito

Integrated Math 1 · Chapter 1 · Lesson 3

Practice Worksheet

Literal Equations and Units

Rearranging a formula for the letter you need.

12 problems · about 21 minutes · A-CED.A.4, N-Q.A.1

NameDate

Figure — use these to answer the problems

Area is length times width. Rearranging that formula gives length as area divided by width.

Area · squares inside

24

Perimeter · walk around

20

4 × 6 = 24 · 4 + 6 + 4 + 6 = 20

Width4
Length6
Figure 1

Warm Up

Straightforward practice. Get the method working first.

5 problems

  1. A = lw with A = 42 and w = 7. What is l?

    Answer

  2. How do units help check a calculation?

    • A wrong resulting unit reveals a wrong setup.
    • They make the arithmetic easier.

  3. A = lw with A = 48 and l = 6. What is w?

    Answer

  4. d = rt with d = 240 and t = 4. What is r?

    Answer

  5. P = 2l + 2w with P = 20 and l = 6. What is w?

    Answer

Build It Up

The same ideas with more to keep track of.

3 problems

  1. C = 2πr with C = 31.4. What is r, using π as 3.14?

    Answer

  2. Miles per hour times hours gives which unit? 1 miles, 2 hours.

    Answer

  3. A = bh ÷ 2 with A = 24 and b = 8. What is h?

    Answer

Stretch Yourself

Mixed problems. Work out what kind of question it is before you start.

4 problems

  1. Match each formula with the rearrangement for the named letter.

    Draw a line from each item on the left to its match on the right.

    • A = lw, solve for w
    • d = rt, solve for r
    • C = 2 pi r, solve for r
    • w = A divided by l
    • r = d divided by t
    • r = C divided by 2 pi

  2. V = lwh with V = 60, l = 5 and w = 3. What is h?

    Answer

  3. The Rearrangement

    A = lw with A = 36 and w = 4. What is l?

    Answer

  4. The Trip

    d = rt with d = 180 miles and r = 60 mph. What is t, in hours?

    Answerhours