Each problem that I solved became a rule
which served afterwards to solve other problems.. Brian Baxter,
American bookseller |
Techniques in studying science and math menu
Solving math word problems
There are two steps to solving math word problems:
- Translate the wording into a numeric equation
that combines smaller "expressions" - Solve the equation!
Suggestions:
- Read the problem entirely
Get a feel for the whole problem - List information and the variables you identify
Attach units of measure to the variables (gallons, miles, inches, etc.) - Define what answer you need,
as well as its units of measure - Work in an organized manner
Working clearly will help you think clearly- Draw and label all graphs and pictures clearly
- Note or explain each step of your process;
this will help you track variables and remember their meanings
- Look for the "key" words (above)
Certain words indicate certain mathematical operations:
Math expressions (examples):
after you
review the keywords, test
yourself
addition: 5+x | subtraction: 5-x |
multiplication: 5*x; 5x | division: 5 ÷ x; 5/x |
Exercise: ("mouse over" the block for answer) | |
Key words for addition
+ increased by; more than; combined together; total of; sum; added to |
|
What is the sum of 8 and y? |
8 + y |
Express the number (x) of apples |
x + 2 |
Express the total weight of |
x + y |
Key words for Subtraction
-
less than, fewer than, reduced by, decreased by, difference of |
|
What is four less than y |
y - 4 |
What is nine less than a number (y) |
y - 9 |
What if the
number (x) of pizzas |
x - 6 |
What is the
difference of my weight (x) |
x - y |
Key words for multiplication
* x or integers next to each
other (5y, xy): of, times, multiplied by |
|
What is y multiplied by 13 |
13y or 13 * y |
Three runners averaged "y" minutes. |
3y |
I drive my car at 55 miles per hour. |
55x |
Key words for division
÷ / per, a; out of; ratio of, quotient of; percent (divide by 100) |
|
What is the quotient of y and 3 |
y/3 or y ÷ 3 |
Three
students rent an apartment |
x/3 or x ÷ 3 |
"y" items
cost a total of $25.00. |
25/y or 25 ÷ y |
More vocabulary and key words:
- "Per" means "divided by"
as "I drove 90 miles on three gallons of gas, so I got 30 miles per gallon."
(Also 30 miles/gallon) - "a" sometimes means "divided by"
as in "When I filled up, I paid $10.50 for three gallons of gasoline,
so the gas was 3.50 a gallon, or $3.50/gallon - "less than"
If you need to translate "1.5 less than x", the temptation is to write "1.5 - x". DON'T! Put a "real world" situation in, and you'll see how this is wrong: "He makes $1.50 an hour less than me." You do NOT figure his wage by subtracting your wage from $1.50.
Instead, you subtract $1.50 from your wage - "quotient/ratio of" constructions
If a problems says "the ratio of x and y",
it means "x divided by y" or x/y or x ÷ y - "difference between/of" constructions
If the problem says "the difference of x and y",
it means "x - y"
What if the number (x) of children was reduced by six, and then they had to share twenty dollars? How much would each get? |
20/(x - 6) |
What is 9 more than y? |
y + 9 |
What is the ratio of 9 more than y to y? |
(y + 9)/y |
What is
nine less than the |
(y + 2) - 9 or y - 7 |
The length of a football field is 30 yards more than its width "y". Express the length of the field in terms of its width y |
y + 30 |