Remarkable / Worksheets / Grade 7 Maths / Functions and relationships: flow diagrams and tables
A one-page CAPS Grade 7 Maths poster on functions and relationships: flow diagrams and tables (Patterns and algebra), with the key ideas, key words and a tip to remember.
A flow diagram takes an input, applies a rule and gives an output.
Rule: multiply by 3, then add 1
Input 4: 4 × 3 = 12, then 12 + 1 = 13
Output = 13
A letter stands for a number. 3x means 3 × x. A formula gives the rule with letters.
y = 4x − 1
When x = 5: y = 4 × 5 − 1 = 19
A table lists inputs and outputs for the same rule. Complete it row by row.
Rule: y = 2x + 7
x = 1, 2, 3 gives y = 9, 11, 13
x: 1, 2, 3 and y: 7, 11, 15
The outputs go up by 4, so start with 4x.
4 × 1 = 4 and 7 − 4 = 3
Rule: y = 4x + 3
To find an input, undo the operations in the opposite order.
y = 4x + 2 and y = 30
30 − 2 = 28
28 ÷ 4 = 7, so x = 7