🎈1. Understanding Estimation

• Estimation: The process of finding an approximate value rather than an exact answer.
• Purpose: Helps in quickly assessing the total amount in real-life scenarios where precise calculations might not be necessary.

🎆2. Steps for Estimating Sums in Word Problems

1. Read the Problem Thoroughly:
   • Identify the numbers involved and what is being asked.
   • Example: “Emma bought 78 apples and 46 oranges. About how many fruits did she buy in total?”
2. Choose an Appropriate Rounding Strategy:
   • Round to the Nearest Ten: Round each number to the nearest ten if the numbers are relatively small.
   • Round to the Nearest Hundred: For larger numbers, round to the nearest hundred if it simplifies the problem.
3. Perform the Estimation:
   • Add the rounded numbers to find the estimated sum.
   • Example:
     • Original Numbers: 78 and 46
     • Rounded Numbers: 80 (78) and 50 (46)
     • Estimated Sum: 80 + 50 = 130
4. Check for Reasonableness:
   • Ensure the estimated sum is sensible given the context of the problem.

🎇3. Example Word Problems

1. Example 1:
   • Problem: “A school has 124 students in one grade and 138 students in another grade. About how many students are there in total?”
   • Solution:
     • Round Numbers: 120 (124) and 140 (138)
     • Estimated Sum: 120 + 140 = 260
2. Example 2:
   • Problem: “A store sold 256 toys in the morning and 183 toys in the afternoon. About how many toys did the store sell in total?”
   • Solution:
     • Round Numbers: 260 (256) and 180 (183)
     • Estimated Sum: 260 + 180 = 440
3. Example 3:
   • Problem: “Liam read 92 pages of his book on Monday and 67 pages on Tuesday. About how many pages did he read in those two days?”
   • Solution:
     • Round Numbers: 90 (92) and 70 (67)
     • Estimated Sum: 90 + 70 = 160

🧨4. Tips for Estimating Sums in Word Problems

• Focus on Key Numbers: Identify the key numbers and approximate them to simplify the addition.
• Select the Best Rounding Method: Depending on the numbers, rounding to the nearest ten or hundred may be more practical.
• Verify Your Estimate: Ensure that the estimated sum is a reasonable approximation of the actual total.

Learn with an example