Times Tables & Strategies 5x 10x - halve or place value strategy

This article is from the 10-article series "Times Tables" strategies. Tables are the strategies taught in the following: 2x, 5x and 10x, 3x, 4x, 1x, 0x, 11x and squares, 9x, 6x, 8x, 7x , 12x.

Facts and 5x 10x facts are closely related. As the facts calculate 10x sunlight, they are included with the 5x facts to practice in it.

The teaching of facts 5x

This is easiest to get to the second set of references to2x facts. To understand this strategy, you need to know your students to a multiple of 10, and can halve the number to 10.

Children often see the pattern in multiples of 5, even before an adult who teaches them. The visual cues, auditory and symbolic events in the 5x is the most obvious in all the facts and still considerably higher number 5x10. The model, of course I am referring to is the one that ends in 5, then 0, then 5, then 0, and so on. Just playing"Twenty, 2005, thirty, thirty, forty, forty-five," and so on is very satisfying and so easy to remember, provided you know the order of ten names.

The question is: "Why are multiples of five end to enter '5 ', '0'? As a child I do not remember, it works, but I remember a teacher told me. But the answer is very simple and will be treated by some students: five to thirty. I know that I already knew, but you can notInternet, this simple fact, the 5x tables. However, this concept at the heart of multiples of 5, and should be the lesson of this strategy, one in the middle. Just know that a pair of tens fives also opens up many possibilities for the numbers multiplied by 5 To do so, halving the multiplier and make it to ten (if not "add a zero", because that is misleading).

An example well beyond the basic facts: 26 multiplied by 5

Half of the 26 of 13

makeTen

13 tens is 130: 5x26 = 130

This is an example of a fact number extended. The knowledge of the strategy for multiplication facts 5x help a student with many examples of extended multiplication facts or basis.

The facts are the remaining 5 times, the multiplier is an odd number of them. These products are in between a pair of tens, and so the response can be developed with this fact. For example, 5x7:

5x6 = 3 orders (half of 6 is 3) =30

5x8 = 4 tens (half of 8 is 4) = 40

5x7 is halfway between 30 and 40: 5x7 = 35

The teaching of facts 10x

The facts are 10x in the first place, not heavy, and secondly, they are learned by students as a learning place values and numbers of dozens of names. Multiplying with the course of ten non-grouping, and the process involved a series of purely dozens. Therefore, no special method for the Conservation of 10x facts are needed, except forremember the names of several orders:

2 log - twenty

3 orders - thirty

4 ten - forty

5 log - fifty

6 orders of sixty -

7 orders - seventy

Ten 8 - eighty

9 Ten - ninety

10 tens - hundreds

Eleven and twelve tens of tens of thousands are simple additions to this list.

Resources

One of the best resources for modeling made 5x ten frames and counters. For every ten frame consists of two rows of five, is a multiple of fiveFill the frame half past ten, so that the frames alternating complete and half full:

5x1: a frame half past ten = 5

5x2: A frame full of ten = 10

5x3 = a full ten frames, frame, ten and a half = 10 + 5 = 15

5x4 = two full ten frames = 20

5x5 = two full ten frames, a past frame half past ten = 20 + 5 = 25

etc.

Next article

The next article in this series is "Times tables strategy 3x - Plus one or more sets. Double"