# ACT Ch11

## 25 terms · Arithmetic

### What are the arithmetic topics tested on the ACT?

Order of Operations, fractions, decimals, ratios, percentages, averages, charts and graphs, and combinations.

### What's an easy way to remember the order of operations?

Please Excuse My Dear Aunt Sally

### What is the order of operations?

First, do the operations in Parenthesis, then Exponents, Multiply, Divide, Add, and Subtract.

### In what order should is the order of operations performed?

From left to right.

### What is the associative law?

When adding or multiplying a string of numbers, you can add them in any order.

### What is the distributive law?

a(b + c)=ab + ac and a(b - c)=ab - ac

### The distributive law....

gives you two ways to get the same result.

Distribute it.

Factor it.

### A fraction is...

another way of expressing division.

### To reduce a fraction...

see if the numerator and the denominator have a common factor.

### Why should you reduce fractions before working with them?

To save time and prevent errors.

### When comparing fractions,

first find a common whole, or denominator.

### What strategy can be used when adding or multiplying fractions on the ACT?

The Bowtie Strategy.

### When multiplying fractions...

line them up and multiply straight across.

Cross-multiply.

### When dividing fractions....

Invert the second fraction and multiply.

### How can an integer be converted into a fraction?

By making the integer the numerator and 1 the denominator.

### When adding or subtracting decimals...

Line up the decimal points and proceed with regular addition or subtraction.

### It helps to add zeros if..

decimal places of some of the numbers have fewer digits.

### When multiplying decimals...

ignore the decimal points at first, then multiply the numbers. Then count all the digits to the right of the decimal points in the original numbers and place it in the answer.

### When dividing decimals...

convert the number you are diving by into a whole number and move the decimals point in the number that is being divided.

### Scientific notation is...

a way to express very large numbers or very small numbers without endless strings of zeros.

### A ratio is...

a part over a part.

### The number of combinations is the...

product of the number of things of each type from which you have to choose.