Math tricks or Math shortcuts can save you time on tests, help you multiply easily, and help on the SAT and ACT. Check out these amazing Math multiplication tricks.
Math shortcut to help multiply large numbers
Two shortcuts for multiplying by 11 quickly
Two different Math tricks to help you multiply two digit numbers
An easy way to multiply three digit numbers
Cross and Vertical Multiplication
This trick allows you to multiply large numbers. For instance,
234
x 432
The secret is that you cross multiply before you multiply the numbers vertically.
You start on the left and multiply 2 x 4 = 8
Next, multiply the next two numbers. In this pair you can cross multiply, 2 x 3 and
3 x 4, then add their products. 6 + 12 =18
The next step is to multiply the next three numbers.
Cross 2 x 2 and 4 x 4 and vertical multiply 3x3 and add the products.
4+16+9 = 29.
Your halfway home, now start grouping numbers one digit to the right of the hundreds digit, and repeat the process.
Cross 3 x2, and 4 x3= 6 +12 =18, and multiply 4 x2 =8
Finally you combine these numbers for your answer.
8 18 29 18 8 ( carry your tens to the left and the final answer = 101,088
The video reviews all of the steps to this method of multiplication.
Math Tricks- Multiplication Shortcuts
Let's start with two digits 23 x11= The first digit in the answer is the first digit, the last digit is the second number, and add the digits for the middle number.
23 x11 = 2 middle term 2 +3=5 and 3 = 253
34 x11 = 3 middle term 4+3 =7 and 4 = 354
Next, lets multiply 234 x11
First digit will be the 2 and the last digit will be 4
Now for the middle digits. Add the numbers to the left.
4+3=7 and 3+2 =5
Solution = 2,574
This shortcut works for multiplying two digits that are close to 100. For example, 97x 93 or 91 x 89
Here is how it works.
Multiply 96 x 94
Step one is to subtract 100 minus each number.
100-96 is 4, and 100 -94 is 6.
Next subtract the answer from step one from the other number.
94 -4 or 96 - 6 for the first two digits of the answer which equals 90
Finally, subtract 100 from your original numbers, and multiply these together.
In this example it would be 4 x6 =24
Combine these together and the answer equals 9,024
This shortcut works well for numbers in the 90's or high 80's.
This trick rounds the numbers to tens, multiplies, and then adds these numbers together. Because the numbers multiply end in zeros, the numbers can be added in your head, or very easily.
44 x22
First multiply 40 x20 = 800 ,then 4 x20 =80 then 4 x20 =80 and finally 4 x 2 =8
In order to make the addition easy you can combine numbers. In this example I would add 80+80 = 160, then 800 +160=960 +8 =968
44 x22 = 968
I find this method easy, fast, and really helpful.
With a little practice this method makes multiplying two or three digit numbers really easy.
Multiply 62 x 63
The first digits of the answer will equal the first two digits multiplied together which equals 36
The last digit of the answer equals the second two numbers multiplied together 2 x3 = 6
Now for the middle terms, you multiply the middle terms, and then the outside terms.6 x2 =12, and 3 x6 = 18 and then combine these terms12 +18 = 30
Combine all of this together, 36 30 6 You will move 3 to the left because you can only have one digit in the middle term. The final answer equals 3906.
I encourage you to watch the video, and you will see this method is easy, and efficient.