## Trade first subtraction method ballpark estimate

00s Subtraction Methods Make a ballpark estimate. Write a number model to show your estimate. Choose at least two problems to solve using the trade-first  Subtraction - Trade-First. Back to previous page. Related Links. Webinar CCSS and EM. Authors of Everyday Mathematics answer FAQs about the CCSS and EM. View the archived webinar. Everyday Mathematics and the Common Core State Standards for Mathematical Practice. Ballpark estimate: 1. Ballpark estimate: 40 - 20 = 20 2. Ballpark estimate: 3. Ballpark estimate: 4. Ballpark estimate: 5. Ballpark estimate: LESSON11 Trade-First Subtraction 3 Date Time longs cubes 10s 1s 2 17 3 7 - 1 9 1 8 Make a ballpark estimate for each problem and write a number model for your ballpark estimate.

## Trade First Subtraction Method. This method is most commonly used in the United States and most parents learned to subtract in a way that is very similar to this

Solve Problems 1–3 using the trade-first method. Solve Problems 4–6 using any method. Use your ballpark estimates to see if your answers make sense. Sample estimates: 12 13 1. 58 39 Ballpark estimate: 60 40 20 19 2. 600 379 Ballpark estimate: 600 400 200 221 3. 2,936 1,657 Ballpark estimate: 3,000 2,000 1,000 1,279 4. 73 37 Ballpark estimate: 70 40 30 36 5. 900 461 Name Date Time Make a ballpark estimate. Use the trade-first subtraction methodto subtract. Compare your answer with your estimate to see if your answer makes sense. 7. 8 64 8. 9 72 9. 56 8 10. 42 7 Practice. 1. 2. 3. Discuss children’s solutions to Problem 1 on journal page 5P. 93 - 58 = 35 blocks Expect that children will use several different methods, which may include modeling with base-10 blocks or other manipulatives, applying various paper-and-pencil methods such as counting up, and using trade-first subtraction. The answer is 7. Make a ballpark estimate to see whether the answer makes sense: 46 is close to 50, and 39 is close to 40. 50 - 40 = 10. 10 is close to the answer of 7, so 7 is a reasonable answer. The trade-first method is one of many ways people solve subtraction problems. Students will use the trade-first algorithm to subtract 2 and 3-digit numbers. They will make ballpark estimate to check subtraction results. Grade level 3, 20 students, one student with visual impairment, one ELL student . Objectives. Students will be able to subtract two 3-digit numbers using the trade-first algorithm

### 00s Subtraction Methods Make a ballpark estimate. Write a number model to show your estimate. Choose at least two problems to solve using the trade-first

Ballpark estimate: 1. Ballpark estimate: 40 - 20 = 20 2. Ballpark estimate: 3. Ballpark estimate: 4. Ballpark estimate: 5. Ballpark estimate: LESSON11 Trade-First Subtraction 3 Date Time longs cubes 10s 1s 2 17 3 7 - 1 9 1 8 Make a ballpark estimate for each problem and write a number model for your ballpark estimate. LESSON Trade-First Subtraction 3 Date Time longs cubes 10s 1s 76 59 longs cubes 10s 1s 35 26 longs cubes 10s 1s 44 27 longs cubes 10s 1s 217 37 1919 18 Make a ballpark estimate for each problem and write a number model for your ballpark estimate. Use the trade-first method of subtraction to solve each problem. 28 31 17 Answer 9 Answer 14 Answer 9 Answer 17 Answer 17 18 Example: HOME LINK 5 12 Make a ballpark estimate. Subtract and show your work. Check to see if your answer makes sense. 1. Use the counting-up method. 754 -299 2. Use the trade-first method. 754 -299 Multiplication. Write facts that you know. 3. × 2 facts 4. × 3 facts 5.× 4 facts 4 × 2= 8 161 Subtraction & Multiplication Practice Unit Solve Problems 1–3 using the trade-first method. Solve Problems 4–6 using any method. Use your ballpark estimates to see if your answers make sense. Sample estimates: 12 13 1. 58 39 Ballpark estimate: 60 40 20 19 2. 600 379 Ballpark estimate: 600 400 200 221 3. 2,936 1,657 Ballpark estimate: 3,000 2,000 1,000 1,279 4. 73 37 Ballpark estimate: 70 40 30 36 5. 900 461