Norman D Lock

Super-Quick Adding and Subtracting in Your Head

By Norman D Lock, Norman Lock

30 Second Challenge: Short Cut to Fractions:Book 3

By Norman D Lock

Short Cuts to Percentages

By Norman D Lock

Multiplying and Dividing

By Norman D Lock

short cuts to fractions

By Norman D Lock

short cuts to fractions

By Norman D Lock

Short Cuts to Percentages

By Norman D Lock

Shortcuts to fractions

By Norman D Lock

The "Daily Mail" 30 Second Challenge: v. 1

By Norman D Lock

The "Daily Mail" 30 Second Challenge: v. 2

By Norman D Lock