Estimating quantities and answers

Worked solution

1. 1

   Choose the nearby hundred for each number.

   $296\approx 300208\approx 200$

   Both replacements are close and easier to add.

2. 2

   Add the easy numbers.

   $300+200=500$

   Adding the hundreds estimates the combined amount.

3. 3

   Label the result as an estimate.

   $296+208\approx 500$

   The original numbers were replaced, so the total is about five hundred.

Worked solution

1. 1

   Use the estimate for one tray.

   $\text{seedlings per tray}\approx 20$

   The six full trays are similar, so use the same estimated amount for each.

2. 2

   Multiply by the number of trays.

   $6\times 20=120$

   Six groups of twenty make one hundred and twenty.

3. 3

   State the estimated total with its unit.

   $\text{total}\approx 120\text{seedlings}$

   The count per tray was approximate, so the combined count is approximate too.