Math 21

Learn Math Part 21

100

Review: five point seven

5.7

200

Example: Gabe has 51 bananas. He ate 25 bananas. then he equally split it between 4 people. How much bananas are in each group?

1. solve the first step 51-25=26

2. solve the second step 26/4=8.5 about 9 bananas

300

Example: 2⁵

1. the 2 is the base, 5 is the exponent. first put is out 2⁵=2x2x2x2x2

2. solve make it smaller 2x2=4, 4x4x2=16x2=32

3⁴

3x3x3x3=9x9=81

400

Example 1: 45000

1. find where you can put a decimal point at 4.5

2. count the the number past the decimal to the right negative is left 4.5x10⁴

Example 2: 7.6x10^-4

1. you have to move the decimal point

2. same thing negative goes left positive goes right 0.00076

6500

6.5x10³

500

Example: 3x=18

1. divide 3x/3=18/3=1=6 x=6

4x=16

x=4

Multi-step Math Problems

100

Teddy bear has 53 likes on Facebook. she got 25 more then lose 13 likes. How many likes does Teddy Bear have now?

53+25=78-13=65 likes

200

Teddy spends 164 hours per month on screen time. next year he wants to reduce the total hours by 3. How many hours will Teddy have per month.

1. 164x12=1968

2. 1968/3=656

3. 656/12=54.6

300

to make the toy gun it cost: bullets: $1.57, Gun Part 1: $15.45, Gun Part 2: $35.63, Gun Part 3: $12.55, Box: $5.66, Plastic: $0.86. To ship it to the store it cost $23.13. How much does it cost to buy it also has a discount for 50% off

1. 15.45+1.57=17.02

2. 35.63+17.02=52.65

3. 52.65+12.55=65.2

4. 65.2+5.66=70.86

5. 70.86+0.86=71.72

6. 71.72+23.13=$94.85

7. 94.85/2=$47.42

400

Luna bake a cake with 6 1/2 gallons of milk. she want 3 gallons and half of 1/2 then she want to add 6/8 gallons. How many gallons will she used?

1. 1/2/2=0.25 or 1/4 3 1/4

2. 3 1/4 + 6/8= 4 gallons

500

Calvin paints pictures and sells them at art shows. He charges $56.25 for a large painting. He charges $25.80 for a small painting. Last month he sold six large paintings and three small paintings. How much did he make in all?

$414.90

Exponents

100

2³

2x2x2=4x2=8

200

3⁵

3x3x3x3x3=9x9x3=81x3=243

300

5⁴

5x5x5x5=25x25=625

400

8³

8x8x8=64x8=512

500

12⁴

12x12x12x12=144x144=20736

Scientific notation

100

760

7.6x10²

200

920000000000

9.2x10¹¹

300

0.0096

9.6x10^-4

400

5.5x10⁵

550000

500

3.2x10^-6

0.000032

variables

100

5x=100

x=20

200

8x=64

x=2

300

55+x=80

x=25

400

15x=90

x=6

500

x/5=25

x=125