standard_description: Use variables to represent numbers and write expressions when solving a real-world or mathematical problem; understand that a variable can represent an unknown number, or, depending on the purpose at hand, any number in a specified set.
problem_activity: Problem 1
Four expressions are shown in the chart below. For each one, write all the ways to read the expressions that you can think of.
{"table": [{"_attributes": {"align": "Center", "class": ["table", "table-bordered"], "style": "width:70%"}, "tbody": [{"tr": [{"td": [{"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${x+2}$$"}]}]}, {"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${x-2}$$"}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "p": [{}, {}, {}]}, {"_attributes": {"style": "text-align:center"}}]}, {"td": [{"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${2x}$$"}]}, {"_attributes": {"style": "background-color:#eeeeee; text-align:center"}, "strong": [{"span": [{"_attributes": {"class": ["math-tex"]}, "_value": "$${x\\div2}$$"}]}]}]}, {"td": [{"_attributes": {"style": "text-align:center"}, "p": [{}, {}, {}]}, {}]}]}]}]}
Problem 2
Two tape diagrams are shown below. The shading indicates subtraction.
[IMG]
Statements a–h below can be used to describe either Diagram 1 or Diagram 2. Match each statement to one of the diagrams.
a.   The difference of
$$4$$
and
$$m$$
b.   The difference of
$$m$$
and
$$4$$
c.
$$4$$
less than
$$m$$
d.
$$m$$
less than
$$4$$
e.
$$4$$
less
$$m$$
f.
$$m$$
less
$$4$$
g.   Subtract
$$4$$
from
$$m$$
h.   Subtract
$$m$$
from
$$4$$
Problem 3
For each verbal statement, write the algebraic expression it describes.
a.   The sum of
$$e$$
and
$$f$$
subtracted from
$$g$$
b.
$$g$$
less than the sum of
$$e$$
and
$$f$$
c.
$$g$$
more than twice
$$f$$


aligns: no