Download M5.1.1 - Round and estimate using whole numbers and decimals

5th Grade Math
Essential Skills Study Guide
Here is a great web site for explanations and practice: http://www.aaamath.com
M5.1.1 - Round and estimate using whole numbers and decimals
Rounded numbers are easier to work with in your head. They are only approximate. An
exact answer can not be obtained with these numbers. Sometimes an exact answer is not
required.
To round a number:
 Find the place to which you want to round the number
 Look at the number to the right - If that number is 0 through 4, the place you want
to round to stays the same. If the number is 5 through 9, the place you want to
round to will go up.
 Copy the number exactly as it is to the place you’re rounding, round that place,
then finish with 0’s
Example: Round 3,785 to the nearest hundred.
The number in the hundreds place is 7, the number to the right of it is 8. This will make
the hundreds place go up. The number rounded to the nearest hundred is 3,800
How to Estimate a sum by rounding.

Round each term that will be added

Add the rounded numbers
IMPORTANT - DO NOT ADD THE TERMS THEN ROUND THE SUM!!! THIS IS
NOT AN ESTIMATE!
M5.1.2 - Construct, read and interpret tables, chats and graphs (line, double bar,
ordered pair).
*Review Chapter 3 of the textbook.
Example 1:
Test Scores
Score
100
80
60
5th
40
20
6th
0
1
2
Test
3
1. Which class had the highest average score on Test 3?
2. Which class had the lowest average on any test, and which test was it?
Example 2:
School Play Attendance
a. Between which two days was there the greatest decrease in attendance?
b. What was the total attendance for all of the play performances?
c. On which day(s) was the attendance less than 325 people?
Example 2: Write the ordered pair for each point.
B_______
R_______
G_______
N_______
K_______
M5.1.3 - Use the distributive property in solving problems
The Distributive Property of Multiplication - In a multiplication problem, think of one
factor as the sum of two addends. Then, multiply each addend by the other factor and
add the products.
Example:
3 x 14 = 3 x (10 + 4)
= (3 x 10) + (3 x 4)
= 30
+ 12
= 42
M5.2.1 - Add, subtract, multiply decimals; divide by a 1 and 2 digit divisor using
whole numbers; decimals with whole number divisor
Decimals are fractional numbers. The decimal 0.3 is the same as the fraction 3/10. The
number 0.78 is a decimal that represents 78/100.
Adding or subtracting decimals is just like adding other numbers.
Always line up the decimal points when adding decimals.
Remember to put the decimal point in the proper place in your answer.
How to multiply a three digit decimal by a one digit decimal number (for example 0.529
* 0.7):

Place one decimal above the other so that they are lined up on the right side. Draw
a line under the bottom number. Temporarily disregard the decimal points and multiply
the numbers like multiplying a three digit number by a one digit number.





0.529
0.7
Multiply the two numbers on the right side. (9 * 7 = 63). This number is larger
than 10 so place a six above the center column and place three below the line in the right
column.






6
0.529
0.7
3
Multiply the digit in the top center column (2) by the digit in the center of the
right column (7). The answer (2*7=14) is added to the 6 above the center column to give
an answer of 20. The units place value (0) of 20 is placed below the line and the tens
place value (2) of the 20 is placed above the five.





26
0.529
0.7
03

The five of the top number is multiplied by the seven of the multiplier (5*7=35).
The two that was previously carried is added and 37 is placed below the line. At the start
we disregarded the decimal places. We must now count up the decimal places and move
the decimal place to its proper location. We have three decimal places in 0.529 and one in
the decimal 0.7 so we move the decimal four places to the left to give the final answer of
0.3703.




26
0.529
0.7
0.3703
M5.2.2 - Find the mean, median, mode and range of a set of data
Mean - the average of a set of data. Add each item, divide the sum by the number of
items.
Median - the number in the middle of a set of data when the data is arranged in order.
Mode - the data item which occurs the most often. A set can have more than one mode or
no mode at all.
Range - the difference between the smallest and largest items in a set of data.
Example: 24, 25, 25, 26, 27, 27, 27, 28, 30
The median is 27, it is in the middle.
The range is 6, the difference between 24 and 30 (30-24=6).
The mode is 27, it occurs three times and more than any other item.
The mean is about 27, the sum is 239, there are 9 items, 239  9  27.
M5.2.3 - Distinguish between similarity and congruence. Recognize similar and
congruent shapes.
Congruent figures - figures that have the same size and shape.
Similar figures - Figure that have the same shape, but not necessarily the same size.
Examples:
These figures are similar. They are the same
shape, but not the same size.
These figures are congruent. They are the same size and
shape