### fact family

1. a set of related addition and subtraction facts 2. a set of related multiplication and division facts

### Fact extensions

Calculations with larger numbers using knowledge of basic arithmetic facts. Fact extensions apply to all four basic arithmetic operations.

### Function machine

An imaginary machine used in EVERYDAY MATHEMATICS to change numbers according to a given rule.

### Input

1. A number inserted into an imaginary function machine, which applies a rule to pair the input with an output. 2. Numbers or other information entered into a calculator or computer.

### Output

1. A number paired to an input by an imaginary function machine applying a rule. 2. Numbers or other information displayed by calculator or computer.

### Parts-and-total number story

A number story in which two parts are combined to find a total. A parts-and-total diagram can be used to keep track of the numbers and missing information in such problems.

### Change diagram

A diagram used in EVERYDAY MATHEMATICS to model situations in which quantities are either increased or decreased by addition or subtraction.

### Change number story

A number story in which an amount is increased ( a change-to-more-story) A change diagram can be used to keep track of the numbers and missing information in such problems

### Counting up method

When you add a number or numbers to an existing number to make it easier to work with

### Algorithm

A set of step-by-step instructions for doing something, such as carrying out a computation or solving a problem. The most common algorithms are those for basic arithmetic computation.