6.AT.4 Lesson 4-5-part2 Apply Day · Set B
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4.5 · Part II

Second Practice Form · Independent Application and Spiral Review

Determine the Whole Given the Part and Percent · Part

Interactive Workbench & Models →
Name: Date: Period: Learning Goal:
■ ADVANCED CONCEPT ANCHOR: 4.5 · Part II
1Finding the Whole Given Part & Percent
2The Structural Procedure
  1. Identify the given part and the percentage it represents
  2. Convert the percent to a decimal or fraction
  3. Divide the part by the percent decimal to find the total whole (100%)
3Mathematical Word Bank
  • Determine the Whole Given the Part and Percent (Hallar el total dados la parte y el porcentaje) — Working backwards from a part and its percent to find the whole amount it came from.
  • Part (Parte) — The amount you already know — the piece of the whole that the percent describes.
  • Whole (Total) — The full amount the percent is measured against. The whole is always 100%.
  • Double number line (Recta numérica doble) — Two lines lined up — dollars on one, percents on the other — so matching marks show the same amount two ways.
  • Equation (Ecuación) — A math sentence with an equal sign. Here it says percent × whole = part, with the whole unknown.
  • Percent (Porcentaje) — A ratio comparing a number to 100. To compute with it, write it in decimal form: 60% = 0.6.
4Watch out
  • A common mistake when finding the whole is multiplying by the percent instead of dividing. For "$42 is 60% of the original price," computing 0.6 × 42 = $25.20 makes the original price SMALLER than the sale price — impossible for a discount. Since percent × whole = part, the whole is found by dividing: 42 ÷ 0.6 = $70. Whenever the percent is less than 100%, the whole must come out larger than the part, so a smaller answer is the tell.
  1. 1 MULTIPLE CHOICE

    (Lesson 4.4) What is 50% of 84?

    1. A42
    2. B50
    3. C34
    4. D168
    0%50%100%
    Work
  2. 2 GUIDED FILL
    50% Model

    50% of a number is 35. Find the whole (the 100%).

    1. 1Write 50% as a decimal: ___.
    2. 2The part ÷ the percent gives the whole: 35 ÷ 0.5 = ___.
    3. 3Check: 50% of 70 = ___.
    Final answer:
  3. 3 MULTIPLE CHOICE

    $9 is 25% of what number?

    1. A$36
    2. B$2.25
    3. C$34
    4. D$225
    0%50%100%
    Work
  4. 4 MULTIPLE CHOICE

    To find the whole from a part and a percent, you…

    1. ADivide the part by the percent in decimal form
    2. BMultiply the part by the percent
    3. CAdd the part and the percent
    4. DSubtract the percent from 100
    ✏️ Workspace & Solution Steps
  5. 5 MULTIPLE CHOICE

    To find the whole when $9 is 25% of it, Lena divides 9 by 0.25. Omar reasons that 25% is a quarter, so he multiplies 9 by 4. Whose method works?

    1. ABoth — dividing by 0.25 and multiplying by 4 are the same operation
    2. BOnly Lena — multiplying cannot undo a percent
    3. COnly Omar — you should never divide by a decimal
    4. DNeither — you need the whole before you can use either method
    ✏️ Workspace & Solution Steps
  6. 6 MULTIPLE CHOICE

    $20 is 50% of what number?

    1. A$40
    2. B$10
    3. C$25
    4. D$70
    0%50%100%
    Work
  7. 7 MULTIPLE CHOICE

    Which equation says "30 is 25% of some number n"?

    1. A0.25n = 30
    2. B25n = 30
    3. Cn = 0.25 × 30
    4. Dn = 30 + 25
    ✏️ Workspace & Solution Steps
  8. 8 MULTIPLE CHOICE

    $42 is 60% of the original price. Should the original price be more or less than $42?

    1. AMore, because 60% is less than the whole
    2. BLess, because 60 is a big number
    3. CExactly $42
    4. DYou cannot tell
    ✏️ Workspace & Solution Steps
📐 CER MATHEMATICAL PROOF MATRIX (CER 2.0) SMP.3 / Proof & Justification

Writing Task: Justify why your mathematical solution is accurate and complete.

C Claim
State your direct mathematical answer/claim with units.
E Evidence
Cite exact numbers, calculations, dimensions, or graph data.
R Reasoning
Explain the mathematical theorem, property, or definition connecting evidence to claim.
Student Mastery Self-Assessment:
1 · Need More Support
2 · Getting Closer
3 · Got It / Solid
4 · Master / Can Teach It