Estimating products

Intros
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Lessons
  1. Example of estimating the product of 49 × 58
  2. Key terms for estimating products
  3. Estimating products by rounding
  4. Estimating products by clustering
  5. Estimating products using compatible numbers
  6. Underestimating and overestimating products
Examples
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Lessons
  1. Estimating Products by Rounding
    Estimate the product using estimation by rounding. Then, find the exact product to check your answer.
    1. 695 × 487 =
    2. 89.32 × 514 =
    3. 0.71 × 2.64 =
    4. 625\frac{2}{5} × 868\frac{6}{8} =
    5. 1119\frac{1}{9} × 3610\frac{6}{10} =
  2. Estimating Products by Clustering
    Estimate the product using estimation by clustering. Then, find the exact answer to check your estimate.
    1. 71 + 68 + 73 + 65 =
    2. 0.318 + 0.299 + 0.256 + 0.341 =
    3. 11710\frac{7}{10} + 1225\frac{2}{5} + 1214\frac{1}{4} + 1112\frac{1}{2} + 1145\frac{4}{5} =
  3. Estimating Products with Compatible Numbers
    Estimate the product using compatible numbers. Is the estimated product less than or greater than the exact product?
    1. 34\frac{3}{4} × 756\frac{5}{6} =
    2. 2535\frac{3}{5} × 58\frac{5}{8} =
  4. Comparing estimated products
    Compare the products by first estimating each product using compatible numbers. Then, use symbols (for less than <, greater than >, or about equal to ≈\approx) to show which product will be greater.

    812\frac{1}{2} × 47\frac{4}{7} vs. 49\frac{4}{9} × 1013\frac{1}{3}
  5. Estimating Products Word Problem - 1
    If a box of twelve mangoes costs $47.88 and weighs 5.34 pounds:
    1. About how much will 350 boxes of mangoes cost? Use the estimation by rounding method.
    2. About how much will 350 boxes of mangoes cost? Use the estimation with compatible numbers method.
    3. Find the exact cost of 350 boxes of mangoes? Are your estimates from part a) and b) more or less than the exact cost?
    4. About how many pounds will 350 boxes of mangoes weigh? Use the estimation by rounding method.
    5. About how many pounds will 350 boxes of mangoes weigh? Use the estimation with compatible numbers method.
    6. Will the boxes of mangoes weigh more than or less than 1,500 pounds? Are your estimates from part c) and d) more or less than the exact cost?
  6. Estimating Products Word Problem - 2
    Elsa used 434\frac{3}{4} flasks full of blue liquid in her science experiment. Charlie wants to use 215\frac{1}{5} times as much as Elsa. About how many flasks of blue liquid would Charlie need for his experiment?
    1. Use the estimation by rounding method to estimate the number of flasks.
    2. Use the estimation with compatible numbers method to estimate the number of flasks.
    3. Calculate the exact product (exact answer) of how many flasks Charlie needs.