7.2 Commutative and associative properties  (Page 4/4)

$8+9=\_\_\_$

$7+6=\_\_\_$

$8(\mathrm{-12})=\_\_\_$

$7(\mathrm{-13})=\_\_\_$

$(\mathrm{-19})(\mathrm{-14})=\_\_\_$

$(\mathrm{-12})(\mathrm{-18})=\_\_\_$

$\mathrm{-11}+8=\_\_\_$

$\mathrm{-15}+7=\_\_\_$

$x+4=\_\_\_$

$y+1=\_\_\_$

$\mathrm{-2}a=\_\_\_$

$\mathrm{-3}m=\_\_\_$

$(11+9)+14=\_\_\_$

$(21+14)+9=\_\_\_$

$(12·5)·7=\_\_\_$

$(14·6)·9=\_\_\_$

$(\mathrm{-7}+9)+8=\_\_\_$

$(\mathrm{-2}+6)+7=\_\_\_$

$\left(16·\frac{4}{5}\right)·15=\_\_\_$

$\left(13·\frac{2}{3}\right)·18=\_\_\_$

$3(4x)=\_\_\_$

$4(7x)=\_\_\_$

$(12+x)+28=\_\_\_$

$(17+y)+33=\_\_\_$

If $y=\frac{5}{8},$ evaluate:

1. ⓐ $y+0.49+(-y)$
2. ⓑ $y+(-y)+0.49$

If $z=\frac{7}{8},$ evaluate:

1. ⓐ $z+0.97+(-z)$
2. ⓑ $z+(-z)+0.97$

If $c=-\frac{11}{4},$ evaluate:

1. ⓐ $c+3.125+(-c)$
2. ⓑ $c+(-c)+3.125$

If $d=-\frac{9}{4},$ evaluate:

1. ⓐ $d+2.375+(-d)$
2. ⓑ $d+(-d)+2.375$

If $j=11,$ evaluate:

1. ⓐ $\frac{5}{6}\left(\frac{6}{5}j\right)$
2. ⓑ $\left(\frac{5}{6}·\frac{6}{5}\right)j$

If $k=21,$ evaluate:

1. ⓐ $\frac{4}{13}\left(\frac{13}{4}k\right)$
2. ⓑ $\left(\frac{4}{13}·\frac{13}{4}\right)k$

If $m=\mathrm{-25},$ evaluate:

1. ⓐ $-\frac{3}{7}\left(\frac{7}{3}m\right)$
2. ⓑ $\left(-\frac{3}{7}·\frac{7}{3}\right)m$

If $n=\mathrm{-8},$ evaluate:

1. ⓐ $-\frac{5}{21}\left(\frac{21}{5}n\right)$
2. ⓑ $\left(-\frac{5}{21}·\frac{21}{5}\right)n$

$\mathrm{-45}a+15+45a$

$9y+23+(\mathrm{-9}y)$

$\frac{1}{2}+\frac{7}{8}+\left(-\frac{1}{2}\right)$

$\frac{2}{5}+\frac{5}{12}+\left(-\frac{2}{5}\right)$

$\frac{3}{20}·\frac{49}{11}·\frac{20}{3}$

$\frac{13}{18}·\frac{25}{7}·\frac{18}{13}$

$\frac{7}{12}·\frac{9}{17}·\frac{24}{7}$

$\frac{3}{10}·\frac{13}{23}·\frac{50}{3}$

$\mathrm{-24}·7·\frac{3}{8}$

$\mathrm{-36}·11·\frac{4}{9}$

$\left(\frac{5}{6}+\frac{8}{15}\right)+\frac{7}{15}$

$\left(\frac{1}{12}+\frac{4}{9}\right)+\frac{5}{9}$

$\frac{5}{13}+\frac{3}{4}+\frac{1}{4}$

$\frac{8}{15}+\frac{5}{7}+\frac{2}{7}$

$(4.33p+1.09p)+3.91p$

$(5.89d+2.75d)+1.25d$

$17(0.25)(4)$

$36(0.2)(5)$

$\left[2.48(12)\right](0.5)$

$\left[9.731(4)\right](0.75)$

$7(4a)$

$9(8w)$

$\mathrm{-15}(5m)$

$\mathrm{-23}(2n)$

$12\left(\frac{5}{6}p\right)$

$20\left(\frac{3}{5}q\right)$

$14x+19y+25x+3y$

$15u+11v+27u+19v$

$43m+(\mathrm{-12}n)+\text{}(\mathrm{-16}m)+(\mathrm{-9}n)$

$\mathrm{-22}p+17q+(\mathrm{-35}p)+(\mathrm{-27}q)$

$\frac{3}{8}g+\frac{1}{12}h+\frac{7}{8}g+\frac{5}{12}h$

$\frac{5}{6}a+\frac{3}{10}b+\frac{1}{6}a+\frac{9}{10}b$

Stamps Allie and Loren need to buy stamps. Allie needs four $\text{\$0.49}$ stamps and nine $\text{\$0.02}$ stamps. Loren needs eight $\text{\$0.49}$ stamps and three $\text{\$0.02}$ stamps.

ⓐ How much will Allie’s stamps cost?

ⓑ How much will Loren’s stamps cost?

ⓒ What is the total cost of the girls’ stamps?

ⓓ How many $\text{\$0.49}$ stamps do the girls need altogether? How much will they cost?

ⓔ How many $\text{\$0.02}$ stamps do the girls need altogether? How much will they cost?

Counting Cash Grant is totaling up the cash from a fundraising dinner. In one envelope, he has twenty-three $\text{\$5}$ bills, eighteen $\text{\$10}$ bills, and thirty-four $\text{\$20}$ bills. In another envelope, he has fourteen $\text{\$5}$ bills, nine $\text{\$10}$ bills, and twenty-seven $\text{\$20}$ bills.

ⓐ How much money is in the first envelope?

ⓑ How much money is in the second envelope?

ⓒ What is the total value of all the cash?

ⓓ What is the value of all the $\text{\$5}$ bills?

ⓔ What is the value of all $\text{\$10}$ bills?

ⓕ What is the value of all $\text{\$20}$ bills?

In your own words, state the Commutative Property of Addition and explain why it is useful.

In your own words, state the Associative Property of Multiplication and explain why it is useful.