Numbers & Operations

Easy

Find each term hidden in the grid. Selecting a word reveals its definition and a link to study it in depth.

7 terms · Choose how you want to study

New to the ATI TEAS 7 exam? Read our how-to-pass guide →

Study modes

Terms in this set

Order of Operations

The required sequence for evaluating expressions: Parentheses, Exponents, Multiplication and Division (left to right), then Addition and Subtraction (left to right) — remembered as PEMDAS.

Grouping symbols include brackets and fraction bars as well as parentheses — the numerator and denominator of a fraction are each evaluated as if wrapped in parentheses before dividing.

Fraction Operations

Adding and subtracting fractions requires a common denominator; multiplying multiplies straight across; dividing multiplies by the reciprocal of the second fraction.

Mixed numbers are usually easiest to convert to improper fractions before operating. To compare fractions quickly, cross-multiply or convert both to decimals.

Decimals & Place Value

Each digit's value depends on its position: places left of the decimal point are ones, tens, hundreds; places right of it are tenths, hundredths, thousandths.

Converting between fractions and decimals is a core TEAS move: divide numerator by denominator to get a decimal, and read a terminating decimal as a fraction over a power of ten (0.45 is 45/100, which reduces to 9/20).

Percentages

A percent is a ratio out of 100; the core relationship is part = percent x whole, which can be solved for any one of the three quantities.

Common benchmark conversions worth memorizing: 1/8 = 12.5%, 1/4 = 25%, 1/3 is about 33.3%, 3/8 = 37.5%, and 2/3 is about 66.7%. They let you estimate answers before computing.

Percent Increase & Decrease

Percent change = (amount of change / original amount) x 100 — the denominator is always the ORIGINAL (starting) value, not the new one.

For successive changes, apply each multiplier in turn: a 10% increase followed by a 10% decrease is 1.10 x 0.90 = 0.99 of the original — a net 1% decrease, not zero.

Ratio

A comparison of two quantities by division, written 3:4, 3/4, or '3 to 4'; ratios can compare part to part or part to whole.

Ratios scale like fractions — multiply or divide both terms by the same number. To split a total in a given ratio, add the ratio parts to find the number of shares, divide the total by that sum, then multiply back out.

Proportion

An equation stating two ratios are equal (a/b = c/d), solved by cross-multiplication: ad = bc.

Proportions power most TEAS word problems: scaling recipes, map distances, medication dosing, and similar figures. Direct proportions rise together; in inverse proportion one quantity rises as the other falls (more workers, less time).