Unit 2 · Exponents & Scientific Notation

Scientific Notation

A number is in scientific notation when it is a × 10^n with 1 ≤ |a| < 10 and n an integer.

Grade 8 State Test
NY-8.EE.3NY-8.EE.4

Notes

Moving the decimal

If you move the decimal left, n is positive (large numbers). If you move it right, n is negative (small numbers). When multiplying, multiply the decimals and add the exponents, then restore 1 ≤ |a| < 10.

Vocabulary

scientific notation

A × 10^n where 1 ≤ |A| < 10 and n is an integer.

Example: The mass of Earth is about 5.97 × 10^24 kg.

Worked examples

Try the prompt first. The steps stay folded until you ask to see them.

Multiply

(3.0 × 10^4)(2.5 × 10^(−2))

Common errors

Watch for

Writing 35.0 × 10^3 and calling it scientific notation

The leading factor must be at least 1 and less than 10.

Fix: Rewrite as 3.50 × 10^4.

Explore with an applet

Guided practice

Submit each answer to check it. The key is not shown until you do.

Question 1 of 3Grade 8 State TestNY-8.EE.1Grade 8 Mathematics · Spring 2022 · Q35Non-calculatorproficient

Which expression is equivalent to 4⁻⁵ × 4⁸?

Answer choices
Choose or type an answer first. The key stays hidden until you do.
Question 2 of 3Grade 8 State TestNY-8.EE.1Grade 8 Mathematics · Spring 2023 · Q15Non-calculatorproficient

Which expression has a value of 1/16?

Answer choices
Choose or type an answer first. The key stays hidden until you do.
Question 3 of 3Algebra I RegentsAI-N.RN.1Algebra I Regents · June 2024 · Q3Non-calculatoremerging

Which equation is always true?

Answer choices
Choose or type an answer first. The key stays hidden until you do.

Intervention

Place-value chart: each move of the decimal is one power of ten.

Enrichment

Compare 4.2 × 10^7 with 6.1 × 10^6 by converting both to the same power.

Explain your reasoning

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  • The exponent is negative because the original number is…