# Grade 3-6 Week 11: Revision Facts: Difference of; 5x, 10x

### Teaching Video:

Once we know the basic number facts, regular revision will help us to retain the skills of fast recall of the facts.

This set of worksheets contains questions which target a variety of strategies:

• Difference of 1, 2 or 3 (addition and subtraction)
• 5x facts (multiplication and division)
• 10x facts (multiplication and division)
• Order of operations: questions with brackets or parentheses

At this level, only the last type of questions will require new learning.
Most adults learned a rule for memorizing the order in which operations should be carried out, where mixed operations are involved:

• PEDMAS
• BOMDAS
• PEMDAS
• BIDMAS

Each of these acronyms spells out the parts of an expression to be carried out, includingParentheses or Brackets; Exponents, Order or Indices; Multiplication; Division; Addition andSubtraction.

Each of these memory tools should be applied carefully, however, because each one omits to indicate that multiplication and division are carried out at the same “level”, working left to right, and similarly so are addition and subtraction.