Classroom activity Grade 8 Math

Powers of Ten Water Line-Up: A Scientific Notation Activity

A grade 8 movement activity where students write water quantities in scientific notation and order them along a power-of-ten number line.

Grade: Grade 8
Subject: Math
Material: Classroom activity
Time: 40 min
Prep: Low prep
Materials: Floor tape or number-line cards labeled 10^0 through 10^10, Quantity cards, Printed Student Handout

Standards

8.EE.A.3 Common Core Math

Use numbers expressed in the form of a single digit times an integer power of 10 to estimate very large or very small quantities, and to express how many times as much one is than the other.

How this material aligns: Students write each water quantity on their card as a single digit times a power of ten and order the cards on a floor number line, then compare how many times as much one card is than another.

All materials for 8.EE.A.3 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will write water quantities in scientific notation.
Students will order quantities by their power of ten and compare their sizes.

Vocabulary

Key words: scientific notation, power of ten, order of magnitude

Teacher overview

This is a whole-class movement activity for 12 to 30 students, run as small groups or pairs. A number line taped across the floor is labeled with powers of ten, and each group holds a card showing a realistic water quantity in standard form, from a single bathtub up to a full reservoir. Groups rewrite their number in scientific notation, then physically stand at the matching power of ten. The line they form shows how many powers of ten separate a bathtub from a city's daily supply.

Activity Directions

Before class, tape a number line across the floor and label marks 10^0, 10^1, 10^2, and so on up to 10^10. This line is the scale every card maps onto.
Split the class into six groups and give each group one quantity card and a copy of the Student Handout.
Each group rewrites the number on its card in scientific notation, checking that exactly one nonzero digit sits to the left of the decimal point.
On your signal, each group sends a member to stand at the power of ten that matches its card, holding the card up.
As a class, read the line from the smallest power of ten to the largest, so every group hears the full order.
Pose the comparison questions from the Student Handout, such as how many times as much the reservoir card is as the water-tower card, and have groups answer using the powers of ten.
Collect the cards, redeal them so each group gets a new quantity, and run one more round for speed.
End after the second round and gather the class near the number line for the debrief.

Debrief: ask which two cards were closest in size and which were farthest apart, and how the powers of ten made the comparison faster than reading the long numbers.

Powers of Ten Water Line-Up: A Scientific Notation Activity — Grade 8 Math

Name: ____________________________ Date: ______________

Student Handout

Write each quantity below in scientific notation. Some are fictional and some are typical figures; the math is the same either way.

Card A: 40 gallons (a full bathtub)
Card B: 300 gallons (about what an average US household uses in a day)
Card C: 9,000 gallons (a backyard pool)
Card D: 500,000 gallons (a town water tower)
Card E: 20,000,000 gallons (about a day's supply for a small city)
Card F: 4,000,000,000 gallons (a reservoir)

Write Card A's 40 in scientific notation.
Write Card B's 300 in scientific notation.
Write Card C's 9,000 in scientific notation.
Write Card D's 500,000 in scientific notation.
Write Card E's 20,000,000 in scientific notation.
Write Card F's 4,000,000,000 in scientific notation.
Order the six cards from least to greatest by their power of ten.
About how many times as much is the reservoir (Card F) as the water tower (Card D)?
About how many bathtubs (Card A) equal one household's daily use (Card B)?
Two pairs of cards are only one power of ten apart. Name both pairs, then use division to decide which pair is closer in size.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

Answer: 4 × 10^1 gallons. 40 = 4 × 10.
Answer: 3 × 10^2 gallons. 300 = 3 × 100.
Answer: 9 × 10^3 gallons. 9,000 = 9 × 1,000.
Answer: 5 × 10^5 gallons. 500,000 = 5 × 100,000.
Answer: 2 × 10^7 gallons. 20,000,000 = 2 × 10,000,000.
Answer: 4 × 10^9 gallons. 4,000,000,000 = 4 × 1,000,000,000.
Answer: A, B, C, D, E, F. Their powers of ten are 1, 2, 3, 5, 7, and 9, which are already in order from least to greatest.
Answer: about 8,000 times. (4 × 10^9) ÷ (5 × 10^5) = (4 ÷ 5) × 10^4 = 0.8 × 10^4 = 8,000.
Answer: about 7.5 bathtubs. (3 × 10^2) ÷ (4 × 10^1) = (3 ÷ 4) × 10^1 = 0.75 × 10 = 7.5.
Answer: A and B (10^1 and 10^2) and B and C (10^2 and 10^3). A and B are closer: 300 ÷ 40 = 7.5, while 9,000 ÷ 300 = 30.

Differentiation

Support

Give supported groups the cards with the smaller quantities (A, B, and C) and a place-value chart so they can count zeros before writing the scientific notation. Let them confirm their spot on the line with a partner before standing.

Extension

Ask fast-finishing groups to add two new cards of their own, one between Card D and Card E in size and one larger than Card F, write each in scientific notation, and place them correctly on the line.

ELL supports

Pre-teach "power of ten" and "order of magnitude" with a labeled example (9,000 = 9 × 10^3). Provide a matching strip that pairs each standard-form number with its scientific-notation form for groups to check against after they write their own.