Unit 1A: Number System Fluency

What's in Unit 1A?

Unit 1A covers the first half of unit 1, which includes multi-digit division of whole numbers and adding, subtracting, multiplying, and dividing with decimal numbers.

REMIND ME! What do decimals mean?

Click the links below for some review

Parts of a Decimal Number

Study Jams: "Order Fractions & Decimals"

How do I add decimal numbers?

Steps:

1. Line up the decimals.

2. If there is a hole, fill it with a zero!

3. Add and bring the decimal straight down.

How do I subtract decimal numbers?

Steps:

1. Line up the decimals.

2. If there is a hole, fill it with a zero!

3. Subtract and bring the decimal straight down.

How do I multiply decimal numbers?

Steps:

1. Line up digits and multiply as if the decimals are not there.

2. Count number of spaces after the decimal in both factors.

3. Count that many spaces (to the right or left) in your quotient (answer) and place your decimal.

How do I divide decimal numbers?

Look at the box on the right if you need review on dividing multi-digit numbers first!

Steps:

1. The divisor must be whole, so.....(if needed, move decimal in divisor to the right to make it a whole number, and move the decimal in the dividend to the right the same number of spaces).

2. Put decimal point directly above the decimal point in the dividend.

3. Divide.