To multiply by 2. To have 2 of something.

Factors of 400 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400. So, 400 can be derived from smaller number in 8 possible ways using multiplication. Factors of 400 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400.

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.

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.

The halving and doubling strategy for multiplication is one of the most fascinating multiplication strategies. To use halving and doubling, you simply half one of the factors and double the other. Take this example. To solve 25×16, we could double the 25 to make 50 and then half the 16 to make 8.

Children. count reliably with numbers from one to 20, place them in order and say which number is one more or one less than a given number. Using quantities and objects, they add and subtract two single-digit numbers and count on or back to find the answer.

How to teach doubles with a mirror:

1. Position one counter in front of the mirror.
2. Add how many counters can be seen altogether including in the reflection of the mirror.
3. Remove the counter, rub out the numbers on the whiteboard.
4. Continue with the activity using however many counters as they wish.

Doubles plus 1 is a strategy used to add two consecutive numbers that is, when they are next to each other. Here, for example, consecutive numbers 8 and 9 have been added using the doubles plus one strategy. Here are more examples of the double plus 1 strategy.

Now, we have to use this fact for 7 + 7. So, we consider 7 + 8 = 15. Hence, the double plus one facts for 7 + 7 is 7 + 8 = 7 + 7 + 1.

What is Double Plus 1? Double Plus 1 is an addition strategy. When one addend is one more than the other addend, we double the smaller addend and add one to get the answer.

Double Facts are additions in which a number is added to itself. For example, 1 + 1, 2 + 2 etc. Internalizing double facts are helpful building blocks in developing fluency in adding single digit numbers. Double Facts within 20 Worksheet is about practicing double facts for numbers up to 10.

Review with your children that a doubles fact is a number sentence that repeats the same addend, such as 3 + 3 = 6 or 8 + 8 = 16. Using manipulatives or other classroom materials, give students opportunities to practice combining groups with the same number.

Well, “the double” of a number is the result of multiplying the number by two (2). By definition, anything multiplied by zero is zero. So, the double of zero is zero.

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3/4 doubled means that you are adding another 3/4 to the original 3/4: 3/4 + 3/4 = 6/4 which simplifies to 1 1/2 (read as 1 and a half). Note that when you double whole numbers you multiple them (in other words, add the number to itself), so 5 doubled is 10 (5×2 or 5+5). 35 doubled to 70.

An increase of 100% in a quantity means that the final amount is 200% of the initial amount (100% of initial + 100% of increase = 200% of initial). In other words, the quantity has doubled. An increase of 800% means the final amount is 9 times the original (100% + 800% = 900% = 9 times as large).