Place value and decimals

Heads up! This course may be archived and/or unavailable.

This course is a part of 5th grade, a 19-course Topic series from Khan Academy.

To really understand how decimal numbers work, we need a deep understanding of place value. The big picture goal of these tutorials is to connect decimal place value to the idea of multiplying by 10.

This course contains 11 segments:

Decimal place value intro

Learn the basics of decimal place value.

Decimals in expanded form

Learn how to write a decimal like 3.14 in expanded form (3 + 0.1 + 0.04).

Decimals in written form

Learn how to write decimals like 3.14 in words as "three and fourteen hundredths".

Comparing decimals

Learn to tell which of two decimal numbers is bigger by thinking about place value.

Rounding decimals

Learn how to round decimal numbers to specific place values. For example, round 3.14159 to the nearest hundredth as 3.14.

Multiplying and dividing whole numbers by 10, 100, and 1000

Learn how to, for example, multiply 560 by 100 to get 56,000.

Multiplying and dividing decimals by 10, 100, and 1000

Learn how to, for example, multiply 34.5 by 100 to get 3450.

Powers of 10

Learn how exponents are a simpler way to write something like 10x10x10.

Multiplying and dividing with powers of 10

Learn how to shift the decimal point when you multiply and divide by powers of ten.

Comparing decimal place values

For a number like 34.135, learn how to compare the 3 in the tens place to the 3 in the hundredths place.

Regrouping decimal numbers

Let's tackle some more challenging problems that stretch our understanding of decimal place value. These problems involve regrouping place values in interesting ways.