Study Guides
Chapter 1
 Chapter 4


Chapter 1
Be able to name the place of an underlined digit  in a number.  For example:

536,769     the 6 is in the thousands place

Take a number from word form to standard form.  For example:

thirteen million, four hundred twenty-three thousand, thirty-seven

13,423,037  Don't forget to use 0 as a place holder!

Go from expanded notation to standard form.  For example:

40,000,000 + 30,000 + 1,000 + 900 + 20 + 2

40,031,922

Order decimals from least to greatest.  Add zeros to the end of the decimals to make comparing easier.  For example:

0.234,  2.07,  0.098, 2.20
Compare the two decimal numbers first: 0.234 and 0.098.  98 is smaller than 234,  so 0.098 goes first, then 0.234.  Now compare 2.07 and 2.20.  7 is smaller than 20, so the 2.07 goes next, then 2.20 last.  

When comparing two numbers, tell which place value determines which number is greater.  For example:

382,618  and 362,470.  Notice that they each have a 3 in the hundred thousands place.  So you would use the ten thousands place to determine which is greater. 8 > 6

Use the practice test in your texbook! 

Chapter 4

Multiply a decimal by a whole number, for example:
46 X 7.2  =

7 .2 One decimal place in the factors.


x 4 6

________


4 3 2

2   8 8 0

________




3 3 1 .2
One decimal place in the product.



Multiply 1.5 X 1.3 X1.4 =

                  Step 1              1.5       Step 2       1.95 
                                           x1.3                           x1.4
                                             45                            780
                                           150                          1950
                                           1.95                         2.730

Estimate: 

0.9 X 8.7 =     Round 0.9 to 1.  Round 8.7 to 9
 
1 X 9 = 9  <------estimate

6.9 X 6.9 =    Round 6.9 to 7.

7 X 7 = 49  <------estimate

Write in exponential form:
   
256 = 2 raised to the 7th power or
            2 x 2 x 2 x 2 x 2 x 2 x 2

Rewrite using a base and an exponent:

16 x 16 x 16 = 16 raised to the 3rd power.

Write in standard form:

0.62 squared =        0.62
                                 x 0.62
                                     124
                                   3720
                                   .3844   <---standard form

Guess and Check:

The distance around a rectangular park is 600 meters.  One side of the park is 50 meters longer than the other side.  How long are the sides of the park?
Try 200 meters and 25o meters. 
                        
2 x 250 = 500
2 x 200 = 400
500 + 400 = 900 too much

Try 100 meters and 150 meters.

2 x 100 = 200
2 x 150 = 300
200 + 300 = 500 too little

Try 125 meters and 175 meters.

2 x 125 = 250
2 x 175 = 350
250 + 350 = 600 just right!