The way mathematics is taught has changed with the use of electronics.Many of the mental math skills taught previously have fallen by the wayside as a result of our reliance on technological aids.When math aids are not available, it is possible to teach students math strategies that will help them quickly add, subtract, multiply, and divide.Students can use these methods to check their work.
Step 1: Understand the value of 0.
Adding zero to a number doesn't change it's value.If I have six apples, and you have zero, we have 6 apples.
Step 2: Understand that property.
Number can be added in any order according to the commutative property.7 apples plus 4 apples is the same as 4 apple plus 7 apple.They both have 11 apples.
Step 3: Count on it.
Count up the value of the smaller number using the commutative property.When one of the addends is less than five, this strategy works best.Students can keep track of how many they have by using their fingers.To calculate 7+3, start with 7 and count on three: seven, eight, and nine.
Step 4: Add three or more numbers and make a ten.
The commutative property can be used to make a ten.To calculate the displaystyle, first make a ten by adding 7 and 3, then add 6 and 6 again.
Step 5: Don't forget doubles.
Adding a number to itself is called a double.If students know how to multiply by two, they can use multiplication to help them add a number twice as big as the original number.Students can memorize doubles up to 10:1.
Step 6: Doubles plus one should be recognized.
A doubles plus one is an addition sentence that is a double, except one number is larger than the other.Students can add 1 to the doubles sum once they memorize their doubles.For example, if a student knows that 6+6 is a display style, they can recognize it.
Step 7: Skip counting can be used.
When adding by twos, fives or tens, students can use skip counting.Students should be aware that any odd number plus two will equal an even number.Five, ten, fifteen are the same as skip counting by fives three times.
Step 8: Think of plus 9 as minus 10.
If you add by 10 instead of 9 you can subtract 1 from the sum.To calculate displaystyle 29+9, use:29+10 as a reference.
Step 9: Make compatible numbers by breaking up larger numbers.
There are compatible numbers that are easier to add together.If you want to calculate 58+32displaystyle, you can break it up into 50+8 and 30-32.The commutative property can be used to add compatible numbers first.
Step 10: Before adding numbers, balance them.
You can add the same amount to both numbers if you subtract one.You could subtract 2 from 30 and then add 2 to 58+32displaystyle.
Step 11: The subtrahend is the number you are subtracting from the minuend.
The result is the answer or difference.Students can use their fingers to count.To calculate 86displaystyle 8-6, start with 6 and see how many you have to count on.
Step 12: For problems that don't require borrowing, use the front end strategy.
To do this, you have to subtract the digits from the place value.You start subtracting from the ones place with pencil and paper.You work from the other direction when you use the front end strategy.If you don't have to borrow from other place values, this strategy will work.If the place values of the numbers are smaller than the digits you are subtracting from, you don't need to borrow.The first thing you would do is subtract the hundreds place, the tens place and the ones place.
Step 13: Break the subtrahend into tens and ones.
Then subtract the group of ones.You can use this strategy to break up numbers into hundreds and tens, or larger place values.To calculate 4224displaystyle 42-24, break up 24 into 20 and 22.
Step 14: Understand the value of 0.
A number will always be the same.5 apples zero times is zero.
Step 15: Understand the value of 1.
The number will always be the same regardless of the number being multiplied by one.5 apples 1 time is 5: 51=5displaystyle
Step 16: You can use the shortcut for multiples of ten.
Adding the number of zeroes in the multiple to the other number is a shortcut.For example: 2710 is a display style of 27 times.
Step 17: The associative property can be used.
You can change the order of groupings if you use the associative property.If you add the 5 and 2 first, you will get a ten, which makes the problem easier.
Step 18: The factor of 5 should be used as half of the factor.
If you want to do this, you have to divide the number by 10 and then half the product.If you change the problem to 2710displaystyle, you can divide the answer in half.
Step 19: Use compatible factors to break up numbers.
The numbers that are compatible are easier to use.To calculate 1258displaystyle, you can factor in 255 and 8 as 42.You can use the commutative and associative property to add up the factors.1258displaystyle 125 times 8(255).
Step 20: One number and the other.
This is another way of finding compatible numbers.Half the 8 could be used to double the 45_845=490 displaystyle.
Step 21: You can use the property.
Break up the number into smaller numbers that can easily be divided by the divisor.Put the quotients together.Break up the 104 into 64 and 40:1048displaystyle to calculate it.
Step 22: The shortcut can be used for multiples of ten.
Simply subtracting the number of zeroes in the multiple from the other number is the shortcut.For example, there is a display style of 27,000.
Step 23: Half the divisor of 10 can be used.
When you divide a number by five, you can divide it by ten, then add the quotient by 2.Divide 1230 by ten and then divide the answer by 2:1.