What is the doubling method?
What is the doubling method?
The doubling strategy is great for multiplication! “Multiply fifteen by four, then add four ones.” “Add together four groups of ten and four groups of six.” “Find four groups of twenty, then subtract four groups of four.” We want students to think as flexibly about numbers and operations as these teachers do.
What is a double fact in multiplication?
Doubling a number twice is the same as multiplying by 4. This strategy relies on knowing the 2x number facts, including some facts beyond the basic single-digit multiplication facts. For example: 8 x 4 = Double 8 = 16 (basic 2x fact)
What is a 3s fact?
The 3’s multiplication facts use students’ knowledge of the doubles addition facts. Students can think of a 3’s equation as “the double plus one more group.” For example, to solve the equation 3×4, think, “the double of 4 plus one more group of 4,” which equals 12.
What is the five is half of 10 strategy?
The use-tens strategy, or the use of multiplication strategies with multiples of 10, highlights that 5 is half of 10, so the product of a fives fact will be half of the product of a related tens fact. This strategy enables the students to easily figure out facts beyond the range of the basic facts.
What 4 doubled?
The double of 4 is 8.
How do you double A set of facts?
To use this strategy, find a set of facts that is known to you. Then, double one factor (or add the number to itself), and double the product, or answer from the first set of facts. For example, let’s imagine there is a Hydra with 4 necks, each neck has 1 head, or 4 x 1=4.
How is doubling used to learn multiplication facts?
So if I have to double 3 to get 6 (my second factor), I also have to double the product. In this situation, if I double the product (15 + 15), I would get 30. So, we have learned to use doubling as a strategy to learn new facts. Take a multiplication fact that you know, double one factor, and then double the product; this will give you your answer.
When do you use a double fact in math?
Any doubled number is a double fact, but double facts are most commonly used when they are small numbers, usually less than 12. The reason teachers use double facts to teach students is because they provide a faster way to find the answer to addition problems that are not as easy to memorize.
Which is the same as double double double?
* Multiplying by 8 is ‘double, double, double’, so 2 x 9 = 18, 2 x 18 = 36 and 2 x 36 = 72. * 9 is 3 squared (‘treble, treble’), and so 3 x 8 =24 and 3 x 24 = 72. o Using addition of known results: 5 x 9 = 45 and 3 x 9 = 27 to give 45 + 27 = 72. o Doubling and halving: 8 x 9 is the same as 4 x 18, which is the same as 2 x 36, which is 72.
