Estimating sums

Intros
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Lessons
  1. Example of estimating the sum of 1617 + 3898
  2. How to round mixed fractions
  3. Key terms for estimating sums
  4. Front-end estimation for sums
  5. Estimation by Rounding for sums
  6. Underestimating and overestimating sums
Examples
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Lessons
  1. Front-End Estimation of Sums
    Estimate the sum using front-end estimation. Then, find the exact sum to check your answer.
    1. 6895 + 2413 + 1878 =
    2. 0.835 + 0.02 + 0.66 =
    3. 36310\frac{3}{10} + 1412\frac{1}{2} + 27 25\frac{2}{5} =
  2. Estimating Sums by Rounding
    Estimate the sum using estimation by rounding. Then, find the exact sum to check your answer
    1. 3128 + 744 + 29 =
    2. 3.78 + 0.94 + 5.261 =
    3. 629\frac{2}{9} + 936\frac{3}{6} + 847\frac{4}{7} + 3111\frac{1}{11} =
  3. Estimating Sums Word Problem - 1
    A pirate finds a map that shows the route to some treasure. The instructions tell the pirate to go: 25.42 km North, then 61.3 km West, and finally 79.018 km North-East.

    • About how many kilometers is the entire route to the treasure?
    1. Write the addition equation that represents this question.
    2. Use the front-end estimation method to estimate.
    3. Use the rounding estimation method to estimate.
    4. Calculate the exact answer.
  4. Estimating Sums Multiple Choice
    Estimate the sum using multiple estimation methods. Then choose the best answer:

    1258\frac{5}{8} + 1145\frac{4}{5} =

    A. Less than 23
    B. Between 23 and 24
    C. Greater than 24
  5. Estimating Sums Word Problem - 2
    This week, Elizabeth ran 315\frac{1}{5} miles on the Monday, 734\frac{3}{4} miles on Wednesday, and 538\frac{3}{8} miles on Friday. About how many miles did she run in total for the week?
    1. Write the addition statement that represents the question.
    2. Use front-end estimation method to estimate.
    3. Use the rounding estimation method to estimate.
    4. Calculate the exact answer.