Arithmetic operations

Let's begin our journey together in 5th grade with good ole fashioned arithmetic. Don't assume that this has to be boring...not at all! We're going to have fun as we learn about and practice adding, subtracting, multiplying, and dividing whole numbers and decimals. We know you're probably pretty comfortable with basic arithmetic, so we'll try to challenge you a little more in these tutorials!

Multiplying decimals

The real world is seldom about whole numbers. If you precisely measure anything, you're likely to get a decimal. If you don't know how to multiply these decimals, then you won't be able to do all the powerful things that multiplication can do in the real world (figure out your commission as a robot possum salesperson, determining how much shag carpet you need for your secret lair, etc.).
3:50
Intro to multiplying decimals
Sal introduces multiplying decimals with problems like 9x0.6.
6:29
Multiplying decimals: place value
Sal uses an understanding of place value to multiply 2.91x3.2.
Article
Multiplying decimals (no standard algorithm)
We'll start with simple problems like 0.9 x 0.2 and build to more complex problems like 3.4 x 6.1.
Exercise
Multiply decimals 1
Multiply tenths like 0.6 x 0.4
Exercise
Multiply decimals 2
Multiply decimals and whole numbers like 8x0.2 or 0.56x4
Exercise
Multiply decimals 3
Multiply numbers with tenths and hundredths like 3.1x3.3 or 1.7x0.12