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Math

Arithmetic and pre-algebra

The first math topic. Start here if you want to learn the basics (or just want to make sure you know these topics). After this, you should be ready for algebra. This topic includes videos from the former developmental math playlists.
Community Questions
A thumbnail for: Addition and subtraction
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Addition and subtraction

Adding and subtracting positive and negative whole numbers. Starts with 1+1=2 and covers carrying, borrowing, and word problems.
A thumbnail for: Multiplication and division
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Multiplication and division

Multiplying and dividing positive and negative whole numbers, understanding place value, and rounding numbers.
A thumbnail for: Factors and multiples
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Factors and multiples

Understanding and finding factors and multiples. After these videos, you'll be ready for fractions.
A thumbnail for: Negative numbers and absolute value
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Negative numbers and absolute value

Extending our understanding of numbers below 0. Thinking about "absolute" distance from 0.
A thumbnail for: Decimals
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Decimals

Understanding decimals conceptually, using operations with decimals, rounding and estimating with decimals, and converting decimals.
A thumbnail for: Fractions
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Fractions

Understanding fractions conceptually, using operations with fractions, and converting fractions.
A thumbnail for: Ratios, proportions, units and rates
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Ratios, proportions, units and rates

A thumbnail for: Applying mathematical reasoning
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Applying mathematical reasoning

You already have many tools in your mathematical toolkit. In this topic, you'll use these in settings that you're likely to encounter in the real world!
A thumbnail for: Exponents, radicals, and scientific notation
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Exponents, radicals, and scientific notation

Understanding and solving exponents without algebra.
A thumbnail for: Arithmetic properties
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Arithmetic properties

This tutorial will help us make sure we can go deep on arithmetic. We'll explore various ways to represent whole numbers, place value, order of operations, rounding and various other properties of arithmetic.
A thumbnail for: Telling time
2 3

Telling time

Learn to tell time with some fun exercises!
A thumbnail for: Measurement
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Measurement

From length to area to volume to time, thinking about how we measure things.