Math problem set Grade 2 Math

Snow to Water at Frostpine Hollow: A Grade 2 Melting Depth Problem Set

Grade 2 students compare snow depth to melted water depth across three storms at Frostpine Hollow, adding and subtracting within 100 to measure this reversible change.

Objectives

  1. Students will subtract within 100 to compare snow depth to melted water depth.
  2. Students will add within 100 to find combined totals across multiple storms.
  3. Students will estimate a reasonable depth based on a pattern in given data.

Vocabulary

Key words: depth, melt, compare, estimate

Teacher overview

Frostpine Hollow (a fictional place used for this problem set) records both the snow depth and the melted water depth after every winter storm, giving students a concrete example of water changing from solid to liquid and back, a reversible change. A common misconception in this set is assuming that a foot of snow melts into about the same depth of water; every storm in this set shows the melted depth is much smaller than the snow depth, and problem 4 asks students to apply that pattern instead of guessing a number close to the snow depth.

Answer Key

  1. Answer: 7 inches less. 8 minus 1 equals 7.
  2. Answer: 10 inches less. 12 minus 2 equals 10.
  3. Answer: Storm 2, by 4 inches. 12 minus 8 equals 4.
  4. Answer: About 1 inch (accept about 1 inch or a little less; 2 inches does not fit, because Storm 1 had more snow than Storm 3 and made only 1 inch of water). Storms 1 and 2 both melted down to a much smaller depth than the snow, so a smaller snowfall like Storm 3's 6 inches should melt down to only about 1 inch of water.
  5. Answer: 26 inches. 8 + 12 + 6 = 26.
  6. Answer: 3 inches. 1 + 2 = 3.
  7. Answer: 6 more inches. 12 minus 6 equals 6.
  8. Answer: 8 inches. 1 + 2 + 5 = 8.

Differentiation

Support

Provide a two-column chart (Snow depth / Water depth) with Storms 1 and 2 already filled in, so students only need to compute the "how many less" subtraction rather than organize the data themselves.

Extension

Ask students to design a Storm 5 with a snow depth of their choosing between 10 and 20 inches, predict a reasonable melted depth using the same pattern, and check that their prediction is much smaller than the snow depth.

ELL supports

Pre-teach "melt," "depth," and "compare" using a simple picture sequence (a snow pile, an arrow, then a small puddle). Allow problem 4's explanation to be given orally to a partner before writing a sentence.