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Introduction to Decimals

Introduction to Decimals — from OpenStax Prealgebra 2e.

Introduction to Decimals

Gasoline price changes all the time. They might go down for a period of time, but then they usually rise again. One thing that stays the same is that the price is not usually a whole number. Instead, it is shown using a decimal point to describe the cost in dollars and cents. We use decimal numbers all the time, especially when dealing with money. In this chapter, we will explore decimal numbers and how to perform operations using them.

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Àwọn Àtòjọ-ẹ̀yàn

Why does the order of operations matter?

Because 2 + 3 × 4 would otherwise be two different numbers. The convention (brackets, exponents, multiplication and division, addition and subtraction) exists so every reader gets the same value from the same expression.

How do I check an arithmetic answer?

Estimate first (round every number and compute roughly), then compare. If the estimate and the exact answer disagree by more than a little, one of them is wrong. The solver shows every operation, so you can find which line went astray.

Why are fractions harder than decimals?

They are not harder, they are more exact: 1/3 is a precise number, 0.333 is an approximation. Fractions need a common denominator to add, which is the one extra step people trip on.

Àwọn ààyè ojú-ìwé yìí tí a fi pamọ́ láti OpenStax Prealgebra 2e (CC BY-NC-SA 4.0). Tí a fi pamọ́ síì níbẹ̀; àwọn àwọn àṣiṣe ní wa. Nítorí pé a tí fi àkóónú rẹ̀ pamọ́ fún ìlòjónú tí kò jẹ́ iṣẹ́ ọ̀fẹ́, ìwé-ìwé yìí jẹ́ ọ̀fẹ̀, kò ní ìfilọ́wọ́, àti àwọn tí a ti pamọ́ fún ìlòjónú kan.

Diẹ̀ nínú Arithmetic

Order of operations Fractions Percentages Powers and roots