Unit 3:Use Place Value to Add and Subtract Numbers

Vocabulary

Place Value: The value of where a digit is in the number. Example: In 352, the 5 is in the "tens" place, so its place value is 10
- Ones
- Tens
- Hundreds
- Thousands
- Ten Thousand
- Hundred Thousands
- Millions
Unit: A general term meaning 1
Digit: A single symbol used to make a numeral.0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 are the ten digits we use in our daily lives.
Base Ten System: Another name for the number system that we use every day.
Compare (<,>,=)
Subtotals: The totals of a certain category
Regroup/Ungroup: Moving an amount (usually 10) from one part of a calculation to another so it is easier to do the calculation.
Expanded Form:
Expanded Notation: Writing a number to show the value of each digit. It is shown as a sum of each digit multiplied by its matching place value (ones, tens, hundreds, etc.)For example: 4,265 = 4 × 1,000 + 2 × 100 + 6 × 10 + 5 × 1
Estimate: To find a value that is close enough to the right answer, usually with some thought or calculation involved.
Addition: Finding the total, or sum, by combining two or more numbers.
Sum (Total): The result of adding two or more numbers.
Addend: Any of the numbers that are added together. Example: In 8 + 3 = 11, the 8 and the 3 are addends.
Subtraction: Taking one number away from another.
Difference: The result of subtracting one number from another. How much one number differs from another.
Standard Algorithm: A specific form of solving math problems that is efficient and always works
Rounding: Rounding means making a number simpler but keeping its value close to what it was. The result is less accurate, but easier to use. Example: 73 rounded to the nearest ten is 70, because 73 is closer to 70 than to 80. But 76 goes up to 80.
Reasonable: Checking to verify that the result of the solution or the calculation of the problem is correct or not, by either estimating or by plugging in your result to check it.
Multi-digit: A number with more than one digit. Example: 345 is a multi-digit number in the hundreds.
Computation: Finding an answer by using mathematics or logic.
Equation: An equation says that two things are equal. It will have an equals sign "="
Variable/Unknown: A symbol for a number we don't know yet. It is usually a letter like x or y.
Operation: A mathematical process. The most common are add, subtract, multiply and divide (+, −, ×, ÷).
Situation Equation: An equation that represents the situation of the story problem.
Solution Equation: An equation that shows the operation needed to solve for the variable.
Comparison Table: A two or more column chart where you can put numbers and data side by side to compare
Number Line: A line with numbers placed in their correct position. Useful for adding and subtracting, and for showing relations between numbers.