The Skills section explicitly lists: "Fluently add and subtract multi-digit whole numbers using the standard algorithm." Student activity pages show vertical alignment and step-by-step standard algorithm work for addition (198 + 117 and 637 + 748 with carrying into the thousands) and subtraction (342 - 167 and three-digit subtraction problems with borrowing). Activities require students to write problems vertically, use composing/carrying and borrowing language, and practice with three-digit, multi-addend, and generated problems up to 10,000.

The lesson explicitly lists as a skill: "Fluently add and subtract multi-digit whole numbers using the standard algorithm." In Activity 2 students are instructed to draw two cards, round them, find estimated sums and differences, and then "find their true sum and difference," allowing them to show work on a whiteboard or scratch paper. The Basic Skills Review includes an exact addition problem (1,547 + 369 = 1,916) that requires computing a multi-digit sum.

Students solve contextual problems that require adding and subtracting multi-digit whole numbers (e.g., finding Carly and Caleb's total 465 + 614 = 1,079 and determining 2,000 - 1,079 = 921). Students compute differences such as how many more Erin collected than Tripp (524 - 365 = 159) and sum multi-month totals for Archie's pages (225 + 145 + 255 = 625). Students are asked to use rounding and estimation to check or guide their answers for these multi-digit computations.

The Skills list explicitly includes "Fluently add and subtract multi-digit whole numbers using the standard algorithm." Students complete many multi-digit addition and subtraction problems on the Unit Review and Unit Test (e.g., 18,564+23,418; 834,277-567,872; 4,207+921; 6,607-1,509). An error-analysis item identifies a missing carry in 4,827+1,676 and gives the correct sum, which calls attention to the carrying step of the addition algorithm.

Students are asked to line up place values and add the ones place first, with explicit mention of composing 10 and regrouping/carrying (intro activity: 4,738 + 2,786 and other examples). Multiple activities require students to perform vertical addition problems with examples and answer keys for five- and six-digit sums (Adding Five-Digit and Six-Digit Numbers) and an example vertical addition (964 + 568). The Nine-Digit Addition Challenge explicitly instructs students to compose 10 and regroup/carry and provides tips for arranging digits to create valid sums, and the Making One Million activity has students find pairs that add to 1,000,000, reinforcing multi-digit addition practice.

The lesson's Skills section explicitly lists fluently adding and subtracting multi-digit whole numbers using the standard algorithm. Students are told to line up place values, write the greater number on top, and use subtraction steps to find differences (examples include 4- and 5- to 6-digit subtractions). Multiple activities require students to solve five- and six-digit subtraction problems (Subtracting Five- and Six-Digit Numbers, Subtraction Ladders) and to check subtraction answers by performing addition (2608 + 3974 = 6582).

The Basic Skills Review #4 asks students to compute a multi-digit addition problem (57,342 + 18,544 = 75,886) and a multi-digit subtraction problem (684,527 − 43,792 = 640,735), and instructs students to show their work using scratch paper. The review also asks students to place commas correctly and to work with place value and rounding, which are related to multi-digit computation skills.

Students are given multi-digit addition and subtraction problems to solve (e.g., $4092+$3146 and $6714−$4380) and an answer key includes larger examples (e.g., $684,527+$43,792 and $57,342−$18,544). An image of subtraction problems with specific error explanations asks students to examine mistakes such as incorrect borrowing and misalignment of place values. Students are asked to complete a "Basic Skills Review" sheet that contains addition and subtraction exercises.

Students complete the "Basic Skills Review #6" items that require multi-digit arithmetic, including 45819 + 6724 and 45819 - 6724, and they are asked to solve other multi-step addition/subtraction problems (e.g., sums and differences in activity answer keys). Activity instructions also remind students to use what they know about addition and subtraction facts as they work, and several worksheet problems require finding missing addends or subtrahends.

The lesson's Skills list explicitly states that students will "Fluently add and subtract multi-digit whole numbers using the standard algorithm." Students solve multiple multi-digit addition and subtraction problems on the Unit 2 Test and review sheets (e.g., 252,127 + 307,811; 435,180 - 389,562; 275,084 + 344,196; 152,300 - 96,295). The student activity pages include instructions to "Add or subtract to answer the questions" and numerous word problems that require multi-digit addition and subtraction.

Students write and solve addition and subtraction equations with multi-digit whole numbers such as 90+90=180 and 45+45=90 when combining angle measures. Worksheets and activities require students to compute problems like 120+35=155, 85+23=108, 155-85=70, and 90-42=48 in the "Adjacent Angles and Equations I/II" tasks. Students complete a "Finding Missing Angles" sheet where they use subtraction (e.g., 80° - 20° = 60°) to find unknown angle measures.

The Basic Skills Review #9 asks students to compute a multi-digit addition: 416,728 + 335,733 = 752,461, and provides scratch paper for work. The review includes other arithmetic items that involve multi-digit numbers (e.g., 4500 + n = 8000 and rounding 45,627), showing some engagement with multi-digit whole-number computations. Students are given individual computation tasks where they must produce exact numeric answers.

Students add multi-digit partial products in several places (for example, reworking 363 × 52 shows 726 + 18150 = 18876, and the expanded-form problems show sums like 820 + 492 = 1312 and 2460 + 205 = 2665). Students also set up stacked addition of partial products in standard-algorithm format when solving and reworking multiplication problems (e.g., shown additions under multiplication setups). The activity asking students to rework errors requires performing multi-digit addition to combine partial products.

Students perform addition when combining metric amounts (e.g., the Carlos problem: 3500 mL + 2 L = 5500 mL). The "Working With Liters and Milliliters" items show conversions written as additions of place-value amounts (e.g., 6 L 124 mL = 6124 mL; 3 L 800 mL = 3800 mL). The Customary Capacity Conversion Charts require converting and comparing totals (e.g., 16 cups vs. 10 pints → 10 pints = 20 cups), which involves computing multi-digit totals after conversion.

The Skills section explicitly tells students to "use the four operations to solve word problems involving...masses of objects, and money," and multiple activity answer keys require adding and subtracting whole-number measures (e.g., 1000 + 500 + 850 = 2350 milliliters; 140 inches − 48 inches = 92 inches). Students also combine converted quantities in problems such as the librarian's books totaling 4800 grams and Kelly's weekly distance totaling 3500 meters (3,500). Several problem answers involve multi-digit whole-number sums or differences (e.g., 2350, 4800, 3500, 4500).

Students subtract the sum of two known sides (30 in.) from the total perimeter (42 in.) to find missing side lengths in the Introduction. The Introduction also instructs students to add all four side lengths to check their work, requiring multi-digit addition when dimensions are larger. In Finding More Areas students perform multi-digit subtraction when computing 2,240 − 800 = 1,440 to find remaining area, and the Mr. Harmon problem requires subtracting twice the known length from the perimeter (240 − 100) before dividing to find the width.

Students solve multiple word problems that require adding multi-digit measurement amounts, such as combining 2500 ml and 2 L to get 4500 ml, totaling juice amounts to 12 cups, summing fruit weights to 66 ounces, and totaling book weights to 5700 grams. Students complete fill-in-the-blank conversion tables and answer questions that require computing totals (e.g., minutes to hours, days to weeks, area calculations) on the Unit 8 Test and Unit 8 Test Review pages. Students are asked to show work using scratch paper or a whiteboard while completing the test items, which implies they perform the arithmetic to combine quantities and compute sums.