Part of the “10 Minutes a Day: Times Tables Worksheets” series
This is the second post, with an attached worksheet to download for your class, on the teaching of times tables.
Free Worksheet 5x & 10x Tables Worksheet A: 5X Facts – Halving Strategy
Worksheet format:The facts are repeated throughout the worksheet with each fact appearing about 8 times. There are some addition and subtraction facts at the bottom to help students to remember those too.
5x Times Tables – Another Easy Set of Number Facts
This is the second easiest set of facts to learn, after 2x. To be able to understand this strategy, your students need to know the multiples of 10, and be able to halve a number up to 10.
Children often recognize the pattern in the multiples of 5 before any adult teaches them. The visual, symbolic and auditory pattern is the most obvious pattern in all the number facts, and continues well beyond 10×5. The pattern I am referring to, of course, is the one that ends in 5, then 0, then 5, then 0, and so on. Just reciting “twenty, twenty-five, thirty, thirty-five, forty, forty-five”, and so on is very satisfying and so easy to remember, provided you know the sequence of tens names.
The question then arises, “Why do the multiples of five always end in ‘5’ or ‘0’?” As a child I don’t remember working it out, and nor do I remember a teacher telling me. But the answer is really simple: five is half of ten. I expect that you knew that already, but you may not have connected that simple fact with the 5x tables. However, this concept is at the heart of the multiples of 5, and should be at the center of a lesson about this strategy. Simply knowing that a pair of fives equals ten opens up myriad opportunities for multiplying numbers by 5. To do so, halve the multiplier and make it into tens (don’t say “add a zero”, because that is misleading).
An example well beyond the basic facts: multiply 26 by 5
- half of 26 is 13
- make it tens
- 13 tens is 130
This is an example of an extended number fact. Knowing the strategy for 5x multiplication facts will help a student with many examples of basic or extended multiplication facts.
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