4.1: Number Talk: Subtracting From Five
Find the value of each expression mentally.
$5-2$
$5-2.1$
$5-2.17$
$5-2\frac78$
Let's solve equations by doing the same to each side.
Find the value of each expression mentally.
$5-2$
$5-2.1$
$5-2.17$
$5-2\frac78$
Solve the equations in one column. Your partner will work on the other column.
Check in with your partner after you finish each row. Your answers in each row should be the same. If your answers aren’t the same, work together to find the error and correct it.
column A | column B | |
---|---|---|
row 1 | $18=2x$ | $36=4x$ |
row 2 | $17=x+9$ | $13=x+5$ |
row 3 | $8x=56$ | $3x=21$ |
row 4 | $21=\frac14 x$ | $28=\frac13 x$ |
row 5 | $6x=45$ | $8x=60$ |
row 6 | $x+4\frac56=9$ | $x+3\frac56=8$ |
row 7 | $\frac57x=55$ | $\frac37x=33$ |
row 8 | $\frac15=6x$ | $\frac13=10x$ |
row 9 | $2.17+x=5$ | $6.17+x=9$ |
row 10 | $\frac{20}{3}=\frac{10}{9}x$ | $\frac{14}{5}=\frac{7}{15}x$ |
row 11 | $14.88+x=17.05$ | $3.91+x=6.08$ |
row 12 | $3\frac34x=1\frac14$ | $\frac75x=\frac{7}{15}$ |
Clare has 8 fewer books than Mai. If Mai has 26 books, how many books does Clare have?
A coach formed teams of 8 from all the players in a soccer league. There are 14 teams. How many players are in the league?
Kiran scored 223 more points in a computer game than Tyler. If Kiran scored 409 points, how many points did Tyler score?
Mai ran 27 miles last week, which was three times as far as Jada ran. How far did Jada run?
Mai’s mother was 28 when Mai was born. Mai is now 12 years old. In how many years will Mai’s mother be twice Mai’s age? How old will they be then?
Writing and solving equations can help us answer questions about situations.
Suppose a scientist has 13.68 liters of acid and needs 16.05 liters for an experiment. How many more liters of acid does she need for the experiment?
Let’s say a food pantry takes a 54-pound bag of rice and splits it into portions that each weigh $\frac34$ of a pound. How many portions can they make from this bag?