ShmoopTube

00:04

Finding and Estimating Square Roots, a la Shmoop.

00:07

Ah, Hansel and Gretel.

00:09

Cooking that witch in "self-defense."

00:12

Little did they know she had security cameras...

00:14

Hansel and Gretels' square-shaped cell is just 18 square feet.

00:18

But these jailbirds have a plan to fly the coop.

00:21

So that was the first plan. Their second plan is dynamite.

00:26

Can you estimate the length of the wall they'll need to blast?

00:30

To find the length of one wall, we need to take the square root of the area, or 18 square feet.

00:35

Unfortunately calculators aren't allowed in maximum security.

00:43

We'll need to estimate.

00:45

To do this, factor out 18.

00:48

Three times six equals 18.

00:50

Factor again until all the numbers are prime.

00:52

This gives us the square root of "three times three times two".

00:56

Now we can pull any "doubles" out of the box. Like those double threes.

01:01

This gives us three times the square root of 2.

01:05

We can't know the exact amount because of that darn "no calculators" rule...

01:10

But we can estimate the value of the square root of two.

01:13

We know that the square root of one is one and the square root of four is two.

01:19

So we know that the square root of two must be a little bigger than one.

01:24

Three times a number a little bigger than one...

01:27

...is a little more than four feet.

01:30

We can now estimate our wall length, which is a little more than four feet.

01:35

Terrific!

01:35

Now Hansel and Gretel can break free and head directly to a Weight Watchers meeting!

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