Category Archives: Math Tricks

Easy 2-digit subtraction tricks

Subtraction Tricks!    Quick subtraction of 2 digit numbers    Subtract both the ten’s and one’s place straight down.  If the one’s is negative, subtract 1 from the ten’s place result, and add 10 to the negative result in the one’s place. These are the ten’s and ones digit of your answer – see the example steps below:    1. […]

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Multiplying teens by teens

Use these easy steps to quickly multiply the any number between 10 and 20 by another number between 10 and 20. Anything from 11-19 – we are talking about some big numbers that you probably aren’t going to memorize – so it helps to have a fast way to do them. The steps may seem a bit ”tricky” at first, […]

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The 11’s trick

A cool math trick to help you multiply many (but not all…) two digit numbers by 11 – very quickly and in your head! Let’s start with a simple example:   11 * 12 = 132 Do you notice anything about the product? (The “product” is what the answer of a multiplication problem is called) See how the answer 132 has […]

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Multiplication by halving and doubling

Sometimes multiplying numbers makes you reach for a pencil and paper… Use this math to help make some bigger problems easier. When given a problem, you can take one of the numbers and cut it in half, and then double the other number. This may result in a combination of numbers that is easier to work with. If one of […]

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multiples of 3 – an answer check and factoring trick

So here is a neat math trick to help make some sense of how numbers combine when dealing with 3 and its multiples (3,6,9,12…).  This falls in the “cool, but wierd, but oddly useful” bucket. Check your multiplication answers Any time you multiply by 3, the digits in the answer will always add up to a multiple of 3.  For […]

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A crazy way to get to 8

This is a fun little math game , see if you can follow the calculations- 1: Think of any number – this is Your Number. 2: Subtract 1 from Your Number. 3: Multiply the answer by 3. 4: Add 12 to the answer. 5: Divide the answer by 3. 6: Add 5 to the answer. 7: Subtract Your Number from the […]

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Multiplying by 9’s

Did you know that when you multiply a 9 by another single digit that the digits of the product will add up to 9? This an easy way to help you remember the multiples of 9 and is helpful in checking your answer.   Let’s take a look: Notice that the 1 and the 8 in the 18 add up […]

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