Lesson 3: Explore Numerical Expressions with Exponents6.AT.5

I can…

I can write and evaluate numbers in exponent form using a base and a power.

Key words

• Powers and Exponents — A power uses a base and an exponent to show repeated multiplication.
• Exponent — A small number that tells how many times to multiply a number by itself.
• Base — The number that gets multiplied by itself.
• Power — A number written with a base and an exponent, like 2³.
• Evaluate — To find the value by putting numbers in for the letters.
• Repeated multiplication — Multiplying the same factor again and again.
• Expanded form — A power written out as a product of its factors.
• Squared — A base used as a factor two times.
• Cubed — A base used as a factor three times.

Steps

1. I want to find the value of 2³.
2. The small 3 tells me to multiply 2 by itself 3 times.
3. So I write 2 × 2 × 2.
4. First 2 × 2 = 4. Then 4 × 2 = 8.
5. So 2³ = 8.

Try it

At a family picnic there are 5 coolers. Each cooler holds 5 bags, and each bag holds 5 juice boxes, so there are 5³ juice boxes. What is the value of 5³?

Check your answer

125

5³ means use 5 as a factor 3 times: 5 × 5 × 5 = 125. Choosing 15 means you multiplied the base by the exponent (5 × 3) instead of repeating the base as a factor. Choosing 53 means you just wrote the base and exponent digits side by side instead of evaluating. Choosing 243 mixes up this base and exponent with 3⁵ (3 × 3 × 3 × 3 × 3 = 243).

Sentence starter

I know ___ because ___.

Goal: I can explain my work using the words exponent, base, power, and evaluate.