Math problem set Grade 4 Math

Winding Creek Water Testing Team: Sampling and Shipping Problems

A grade 4 math problem set where a fictional student water-testing team multiplies sites by bottles and visits, then divides samples among shipping cases with remainders.

Objectives

  1. Students will multiply site counts, bottles per site, and visit counts to find total water samples collected.
  2. Students will divide a total number of samples by a shipping case capacity and interpret the remainder to determine how many cases are needed.

Vocabulary

Watershed
A watershed is all the land where rain that falls will drain to the same stream, river, or lake. Everyone lives in a watershed, no matter how far from the water they live.

Also: sample, site, remainder

Teacher overview

A fictional student water-testing team at Winding Creek collects small sample bottles at several sites along the creek throughout a season, modeled on the way real watershed-monitoring volunteers work. This problem set follows the team through a season of visits, multiplying to find how many samples they collect, then dividing that total among shipping cases and interpreting the remainder. A common misconception in this kind of problem is assuming that leftover samples that do not fill a whole case can simply be left behind, when in reality every sample still needs to be shipped, which means a partial case still counts as a full case for planning and cost purposes.

Answer Key

  1. Answer: 18 bottles.
    6 sites × 3 bottles per site = 18 bottles.

  2. Answer: 72 bottles.
    18 bottles per visit × 4 visits = 72 bottles.

  3. Answer: 9 full cases, no bottles left over.
    72 ÷ 8 = 9, since 8 × 9 = 72 exactly, with no remainder.

  4. Answer: 21 bottles.
    7 sites × 3 bottles per site = 21 bottles.

  5. Answer: 93 bottles.
    72 bottles (problem 2) + 21 bottles (problem 4) = 93 bottles.

  6. Answer: 11 full cases, 5 bottles left over.
    93 ÷ 8: 8 × 11 = 88, and 93 − 88 = 5. So there are 11 full cases and 5 leftover bottles that do not fill a case on their own.

  7. Answer: 12 cases.
    The 11 full cases from problem 6 plus 1 more case for the 5 leftover bottles equals 12 cases the team will be charged for, since a partly filled case still counts as a full case.

  8. Answer: More bottles, by 3.
    New plan: 5 sites × 3 bottles per site = 15 bottles per visit; 15 bottles × 5 visits = 75 bottles. Comparing 75 to the original 72 bottles: 75 − 72 = 3, so the new plan collects 3 more bottles than the original plan.

Differentiation

Support (below grade level)

Provide a printed table with columns for "sites," "bottles per site," "visits," and "total bottles" so students can fill in each number before multiplying, reducing the number of steps they must track in their head at once.

Extension (above grade level)

Ask students to find a combination of sites, bottles per site, and visits (different from any used in this problem set) that produces a season total between 90 and 100 bottles, and to show the multiplication that proves their combination works.

ELL supports

Pre-teach "site," "sample," and "remainder" using a simple map showing numbered dots along a creek, with small bottle icons at each dot to represent samples collected. Provide a sentence frame: "The team collects ___ bottles because there are ___ sites and ___ bottles at each site."