A volunteer smiles beside donated canned food in a school gym

The Power of Ten

The school food drive collected 700 cans! Each crate holds 70 cans. How many crates do we need?

4th Grade Math

Step 1: Compare 4 and 40

Let's analyze the digit 4. On the left, each block is 1, so the 4 is worth 4. On the right, each block becomes a whole row of ten, so the 4 is worth 40. How many times greater is 40 than 4?

4 × 10 = 40. When a digit moves one place to the left, its value becomes 10 times greater.

Step 2: Jump by 70s

0

70

140

210

280

350

420

490

560

630

700

Now think bigger. Start at 0 and count the jumps of 70 on this number line. How many jumps of 70 does it take to reach 700?

70 × 10 = 700. The product of 70 and 10 is 700, because 700 is ten times 70.

Step 3: Solve the Crate Problem

We collected 700 cans. Each crate holds 70 cans. You already know 700 is ten times 70. Use that fact!

700 ÷ 70 = ?

700 ÷ 70 = 10. The quotient is 10 because 700 is ten times 70. We need 10 crates!

Let's Remember

The Place Value Rule

          Move LEFT one place: the digit is worth 10 times MORE.

          Move RIGHT one place: the digit is worth 10 times LESS.

          This pattern works in every place of every number!

7 → 70 → 700 → 7,000

Each arrow means × 10. The digit stays the same, but its value grows.

Watch Out!

A Common Mistake

          Some students say the 6 in 600 is 100 times the 6 in 60. Not true!

          600 is only ONE place to the left of 60.

          One place means 10 times: 60 × 10 = 600.

Count the place jumps first. One jump = 10 times.

Solve It!

800 ÷ 80 = ?

800 ÷ 80 = 10. The 8 in 800 is worth ten times the 8 in 80.

Word Problem

A small jar holds 30 marbles. A large bin holds 300 marbles. How many jars would fill the bin?

300 ÷ 30 = 10. Since 300 is ten times 30, exactly 10 jars fill the bin.

What Goes in the Blank?

60 × ? = 600

60 × 10 = 600. Multiplying by 10 moves the digit 6 one place to the left.

Same Digit, Different Value

Look at 4,455. One 4 is in the thousands place. The other 4 is in the hundreds place. The thousands 4 is worth how many times the hundreds 4?

The first 4 is worth 4,000. The second 4 is worth 400. And 400 × 10 = 4,000.

Digit Detective

In 62, the digit 6 is worth 60. Which number below has a 6 worth ten times that?

In 641, the 6 is in the hundreds place, so it is worth 600. And 60 × 10 = 600.

Challenge!

Look at 5,050. One 5 is in the thousands place. The other 5 is in the tens place. Can you determine how many times greater the thousands 5 is?

The first 5 is worth 5,000. The second 5 is worth 50. That is TWO place jumps: 10 × 10 = 100 times!

Money uses the power of ten, too! How are a dime, a dollar, and a ten-dollar bill like the places in a number?

Great Work!

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analyze determine pattern product quotient