Learning to Juggle with: I juggled

Granny’s chinateacups…..

once!

PowerP

oint© Mike’s Math Mall

0.25110%

40% 𝟎 .𝟒

A percentage represents

an amount out of 100.

So, for example,instead of saying Sparkygot 25 out of 100 on his lastmath test, we say Sparky got a 25%.

We use the (%) symbol instead of writing fractions with a denominator of 100.

It’s timewe find another

example!

Because a percentage representsan amount out of 100, to turn a decimal into a percent, all we do

ismultiply the decimal by 100.Let’s change 0.62 to a

percent! 100× 0.62 200 + 600 62.00= 62 Don’t forget

the percent sign!62%

Someonetold me that when

you multiply by 100, it’sjust like moving the

decimal point 2 placesto the right!

That someone was correct!

Movingthe decimal

seems waaaaay easier to me!

It is! Just don’t forget to add the percent sign after you

move the decimal!

So, let’s use Sparky’s method to easily change some decimals into

percents.0.45 = 45%→ 45.00.7Before we can move the decimal 2 places to the right, we have to add a

zero.

Example 1:

Example 2: 0 → 70.0= 70%

00Example 3:1.25 → 125.0 = 125%

Example 4:2An “understood”

decimal comes after the 2.

.Add two zeros so we can move the

decimal!

→ 200.0 = 200%I’mpretty sure I

have this!

We better practice just to be sure!

Change the following decimals into percentages.1) 0.753) 0.85) 1.457) 0.6159) 0.5

2) 0.114) 0.3336) 0.28) 410) 0.99

= 75%= 80%= 145%= 61.5%= 50%

= 33.3%= 11%= 20%= 400%= 99%

Me thinksme gettin’

dizzy!

This won’t be bad. Trust me!

If we move the decimal 2 places to the right to change a decimal to a percent, what do you suppose we do to change a percent back to a

decimal?Move the

decimal 2 placesto the left?

%%

Example 1:85Locate the “understood”

decimal after the 5 and remove the

percent sign.

%.Then, move the

decimal 2 places to the left.

→ .85 = 0.85Example 2:30 . → .30 = 0.3

Example 3:115 . = 1.15 Your turn!

Change the following percents into decimals.1) 18%3) 5%5) 88%7) 150%9) 316.2%

2) 100%4) 12.9%6) 7.43%8) 11%10) 7.7%

= 0.18 = 1= 0.05 = 0.129= 0.88 = 0.0743= 1.5 = 0.11= 3.162 = 0.077

0.25First, change the fraction into a decimal. (Divide the numerator by the denominator)

Now, change the decimal into a percent. (Multiply by 100, or move the decimal 2 places to the right and add a % sign)0.25 = 25%

0.25First, change the percent into a decimal. (Divide by 100 or move the decimal 2 places to the left)

Now, change the decimal into a fraction0.25 25%

=