A way to write tenths, hundredths, and other decimal fractions as numerals with digits and a decimal point. The digits to the left of the decimal point show the whole-number part of the number. The digits to the right of the decimal point show the fractional part less than 1.

Examples:

written in decimal notation is 0.3.

written in decimal notation is 0.25.

written in decimal notation is 1.7.

written in decimal notation is 2.07.

A way of writing a number as a sum of the values of the digits.

Example: 482 written in expanded form is  .

To say which number a given number is closer to. Example: For 182, the number 180 is the closest multiple of 10, and 200 is the closest multiple of 100. We can round 182 to 180 (if rounding to the nearest ten) or 200 (if rounding to the nearest hundred).

A set of steps used to add or subtract numbers by place value. Write the numbers vertically with digits lined up by place value. Add or subtract the digits in each place value, starting with the least place value. Compose or decompose units, as needed in each place value.