Expressions, like terms and substitution

Build expressions with algebra tiles, collect like terms, cancel zero pairs, then substitute a value for x.

Guide

This studio follows KS3 algebra: writing and simplifying expressions by collecting like terms, and substituting numbers into expressions.

The tiles: a big square is x2, a long strip is x, and a small square is 1. A red tile is the negative of the same tile: a red strip is −x.

An algebraic expression such as 2x + 3 has two terms. In 2x, 2 is the coefficient and x is the variable; 3 is the constant.

like terms have the same letters with the same powers, so they are the same shape of tile: 3x and −x are like terms, but x and x2 are not.

A white tile and a red tile of the same shape make 0: a zero pair. Tap one, then the other, to take them off. Tiles of different shapes never cancel.

To substitute, flip the tiles: each strip shows the value of x. A red tile means take that amount away. Type your answers on the keypad under the tiles.