Transcript 2 Steps - McGraw Hill Higher Education

WHOLE NUMBERS: HOW TO
DISSECT AND SOLVE WORD
PROBLEMS
Chapter One
1-1
McGraw-Hill/Irwin
Copyright © 2014 by The McGraw-Hill Companies, Inc. All rights reserved.
LEARNING UNIT OBJECTIVES
LU 1-1: Reading, Writing, and Rounding Whole Numbers
1.
Use place values to read and write numeric and verbal
whole number s.
2.
Round whole number s to the indicated position.
3.
Use blueprint aid for dissecting and solving a word
problem.
LU 1-2: Adding and Subtracting Whole Numbers
1.
Add whole number s; check and estimate addition
computations.
2.
Subtract whole numbers; check and estimate subtraction
computations.
LU 1-3: Multiplying and Dividing Whole Numbers
1.
Multiply whole number s; check and estimate
multiplication computations.
2.
Divide whole number s; check and estimate computations.
1-2
WHOLE NUMBER PLACE-VALUE
CHART
1,605,743,891,412 displayed on the Whole Number Group Chart:
1-3
WRITING NUMERIC AND VERBAL
WHOLE NUMBERS
1,605,743,891,412 verbalized:
One trillion, six hundred five billion, seven hundred forty-three
million, eight hundred ninety-one thousand, four hundred twelve
1-4
CONVERTING PARTS TO A REGULAR
WHOLE NUMBER
Convert 2.3 million to a
regular whole number.
Step 1. Drop the decimal
point and insert a comma.
Step 2. Add zeros so the left most digit ends in
the word name of the amount you want to
convert. Be sure to add commas as needed.
2,3
2,300,000
1-5
ROUNDING WHOLE NUMBERS
Step 1. Identify the
place value of the
digit you want to
round.
9362
Step 2. Identify the digit to
the right.
9362
If 5 or more, increase the
identified digit by 1, if less
than 5 do not change.
9462
Step 3. Drop all digits to the
right of the digit you want to
round.
9400
1-6
ROUNDING ALL THE WAY
Step 1. Identify the left most digit.
7843
Step 2. Identify the digit to the right.
7843
If 5 or more, increase the left-most
digit by 1; if less than 5, do not
change.
Step 3. Change all other digits to zero.
7843
8000
1-7
HOW TO DISSECT AND SOLVE A WORD
PROBLEM
Organization and persistence
1-8
GENERAL PROBLEM-SOLVING
PROCEDURE
Step 1 . State the problem(s).
Step 2. Decide on the best method(s) to solve the problem(s).
Step 3. Does the solution make sense?
Step 4. Evaluate results.
1-9
HOW TO DISSECT AND SOLVE A
WORD PROBLEM
Tootsie Roll Industries’ sales reached one hundred ninetyfour million dollars and a record profit of twenty-two million,
five hundred fifty-six thousand dollars. Round the sales and
profit figures all the way.
Sales: One hundred ninety-four million dollars. ----------->$194,000,000 -----------> $200,000,000
Profit: Twenty-two million, five hundred fifty-six thousand dollars --------> $22,556,000 ---------> $20,000,000
1-10
ADDING WHOLE NUMBERS
3 Steps
1 . Align the numbers according to
their place values.
Example
1,362
5,913
2. Add the units column.
Write the sum below the
column. If the sum is more
than 9, write the units digit
and carry the tens digit.
8,924
6,594
22,793
3. Moving to the left, repeat Step 2 until all
place values are added.
1-11
ALTERNATIVE CHECK
Add each column as a separate
total and then combine. The
end result is the same.
1,362
5,913
8,924
6,594
Ones Column
2+3+4+4
Tens Column
6+1+2+9
Hundreds Column
3+9+9+5
Thousands Column
1+5+8+6
13
18
26
20
22,793
1-12
ESTIMATE ADDITION BY ROUNDING
ALL THE WAY
Example
Example
211
1,362
1,000
5,913
6,000
8,924
9,000
6,594
7,000
22,793
23,000
*Final answer could have
more than one non-zero since
total is not rounded all the
way.
1-13
SUBTRACTING WHOLE NUMBERS
3 Steps
1 . Align the minuend and subtrahend by
place values.
2. Begin the subtraction with the units digits.
Write the difference below the column.
If the units digit in the minuend is smaller
than the digit in the subtrahend, borrow
1 from the tens digit in the minuend.
3. Moving to the left, repeat Step 2 until all
place values in the subtrahend are
subtracted.
Example
130 (Minuend)
- 60 (Subtrahend)
70 Difference
Check
70
+60
130
1-14
MULTIPLICATION OF WHOLE NUMBERS
4 Steps
1. Align the multiplicand and multiplier at
the right.
Example
418 (Multiplicand)
x 52 (Multiplier)
2. Multiply the right digit of the multiplier with the
right digit of the multiplicand. Keep
multiplying as you move left through the
multiplicand.
836
1-15
MULTIPLICATION OF WHOLE NUMBERS
3. Your partial product right digit or first digit
is placed directly below the digit in the
multiplier that you used to multiply.
4. Continue steps 2 and 3 until the
multiplication process is complete. Add
the partial products to get the final
product.
2,090 (Partial Product)
21,736 (Product)
1-16
CHECKING AND ESTIMATING
MULTIPLICATION
Check
Check the
multiplication
process by
reversing the
multiplicand and
multiplier and then
multiplying.
52
Estimate
50
x 418
416
52
x
400
20,000
20 8
21,736
1-17
MULTIPLICATION SHORTCUT WITH
NUMBERS ENDING IN ZERO
Example
3 Steps
65000 (3 zeros)
x 420 (1 zero)
1. When zeros are at the end of the
multiplicand or the multiplier, or
both, disregard the zeros and
multiply.
2. Count the number of zeros in the
multiplicand and multiplier. (4)
(4 zeros)
Solution
65
x 42
130
260
27,300,000
3. Attach the number of zeros counted in Step 2
to your answer.
1-18
MULTIPLYING A WHOLE NUMBER
BY A POWER OF 10
2 Steps
1. Count the number of zeros in the power of 10.
2. Attach that number of zeros to the right side of the other whole number to obtain
the answer. Insert commas as needed.
99 x 10
99 x 100
99 x 1,000
= 990 = 990 <----Add 1 Zero
= 9,900 = 9,900 <----Add 2 Zero
= 99,000 = 99,000 <----Add 3 Zero
1-19
DIVISION OF WHOLE NUMBERS
 Count how many times
one number (Divisor) is
contained in another
number (Dividend). The
result is the Quotient.
Example
18
Divisor
15 270
Quotient
Dividend
15
120
120
0
1-20
DIVISION OF WHOLE NUMBERS
 Count how many times
one number (Divisor) is
contained in another
number (Dividend). The
result is the Quotient.
Example
24 R 1
Divisor
7
169
Quotient
Dividend
14
29
28
1
1-21
ESTIMATING AND CHECKING DIVISION
Check
138
x 36
828
4 14
4,968
+ 111
Divisor
Example
36 R 111
Quotient
138 5079
Dividend
414
939
828
111
5,079
Estimate
50
100 5,000
1-22
DIVISION SHORTCUT WITH NUMBERS
ENDING IN ZEROS
2 Steps
1. Count the number of ending zeros in the divisor.
2. Drop the same number of zeros in the dividend as in the divisor, counting
from right to left.
95,000 / 10 -- 95,000
95,000 / 100 -- 95,000
95,000 / 1,000 -- 95,000
= 9,500 <----Drop 1 Zero
= 950 <----Drop 2 Zeros
= 95 <----Drop 3 Zeros
1-23