Additional Arithmetic Rules: Applying the formula

According to the order of operations, we first solve the exercise within parentheses:

$30-21=9$

Now we obtain:

$100-9=91$

According to the order of operations, we first solve the exercise within parentheses:

$2\times2=4$

Now we divide:

$12:4=3$

According to the order of operations, we first solve the exercise within parentheses:

$7+4=11$

Now we subtract:

$13-11=2$

According to the order of operations, we first solve the exercise within parentheses:

$28-3=25$

Now we obtain the exercise:

$22-25=-3$

According to the order of operations, we first solve the exercise within parentheses:

$4+9=13$

Now we obtain the exercise:

$28-13=15$

According to the order of operations, we first solve the exercise within parentheses:

$4-7=-3$

Now we obtain:

$37-(-3)=$

Remember that the product of a negative and a negative results in a positive, therefore:

$-(-3)=+3$

Now we obtain:

$37+3=40$

According to the order of operations, first we solve the exercise within parentheses:

$18+20=38$

Now, the exercise obtained is:

$38-38=0$

According to the order of operations, we first solve the exercise within parentheses:

$8+21=29$

Now we obtain the exercise:

$55-29=26$

We write the exercise in fraction form:

$\frac{60}{10\times2}=$

Let's separate the numerator into a multiplication exercise:

$\frac{10\times6}{10\times2}=$

We simplify the 10 in the numerator and denominator, obtaining:

$\frac{6}{2}=3$

We write the exercise in fraction form:

$\frac{60}{5\times3}$

We break down 60 into a multiplication exercise:

$\frac{20\times3}{5\times3}=$

We simplify the 3s and obtain:

$\frac{20}{5}$

We break down the 5 into a multiplication exercise:

$\frac{5\times4}{5}=$

We simplify the 5 and obtain:

$\frac{4}{1}=4$

According to the order of operations rules, we first solve the expression inside of the parentheses:

$15-10=5$

We obtain the following expression:

$66-5=61$

According to the order of operations, we first solve the exercise within parentheses:

$4+2=6$

Now we solve the rest of the exercise:

$7-6=1$

According to the order of operations, we first solve the exercise within parentheses:

$4-12=-8$

Now we obtain the exercise:

$80-(-8)=$

Remember that the product of plus and plus gives us a positive:

$-(-8)=+8$

Now we obtain:

$80+8=88$

According to the order of operations, we first solve the exercise within parentheses:

$2+1=3$

Now we solve the rest of the exercise:

$8-3=5$

According to the order of operations, we first solve the exercise within parentheses:

$17-3=14$

Now we obtain the exercise:

$-33-14=-47$

We write the exercise in fraction form:

$\frac{35}{2\times7}=$

We separate the numerator into a multiplication exercise:

$\frac{7\times5}{2\times7}=$

We simplify the 7 in the numerator and denominator, obtaining:

$\frac{5}{2}=2\frac{1}{2}$

According to the order of operations, first we solve the exercise within parentheses:

$8+10=18$

Now we obtain the exercise:

$-45-(18)=$

We open the parentheses, remember to change the corresponding sign:

$-45-18=-63$

According to the order of operations, we first solve the exercise within parentheses:

$53-18=35$

We obtain the exercise:

$49-35=14$

According to the order of operations, we first solve the exercise within parentheses:

$13-8=5$

Now we obtain the exercise:

$5-5=0$

According to the order of operations, we first address the innermost parentheses.

Remember that the product of a negative and a negative results is positive:

$-(-4)=+4$

Therefore, the exercise we get is:

$70-(32+4)=$

Now, we solve the exercise within the parentheses:

$32+4=36$

We obtain:

$70-36=34$