Elementary Math 201 Mind Map

-When rounding you dont want the exact number your going for a number that is close.-An example of this would be:18+11=?-Round 18 to 20-Round 11 to 10-When adding that up you get 20+10=30The real answer is 29 so your only one off which is close

With this method you are only add and roudn the number in the fathest place value to the left. Then use the rounding method and add to solve

In base 5 addition the highest digit you can use is 4 so you can use 0,1,2,3,4 if it was base 8 the highest digit you could use would be 7

-With Base 5 Subtraction its the same as addition with the digit values cant exceed 4 the only difference is now that you subtract.

-GCF stands for Greatest Common Factor-LCM stands for Least common Multiple

For any two nonzero whole numbers a and b, the greatest commom factor, written GCF(a,b) is the greatest factor (divisor) of both a and b

-More of a basic method that you always use a factor tree is a great visual and for learners that liek to use the step by step procces.

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-Also known as the number line method-This method is a way of showing you if your a more visual learner and like to see drawings infront of you.-In this process you can add using pieces to see when 2 numbers reach eachother again for example:Numbers: 2,4 the next time they will reach eachother will be at 12 because 2*6=12 and 4*3=12

For any two nonzero whole numbers a and b, the least common multiple, rritten LCM9a,b) is the smallest multiple of both a and b.

-Great visual for learners who need to see it layed out infront of them.

The Babalonian system has a very basic way of doing things there is no place holder in this method.

-The eye looking thing represents 0.-So as you can see the dot represents 1. -The rectangle represents 5.

Compatible numbers are well matched the reason for why she showes 15 and 5 becuase it can be divided by 3 fully with no decimals.

-For equal products its also called the adjustment method and basically what it does is shows us a better way of estimating numbers for example:(1/2)36+5(2)= 28= 18+10

There are 3 basic wasy of doing algoirthms there is Left to Right, Partial Sums, and Right to Left. We are going to talk about the basica types with addition and subtraction.

With left to right its very easy to pick up on its like basic addition but you are starting on the left instead of right liek you normally would.

-As you can see see for the 9 and 4 they put a 0 next to it because it was in the tens. So it made it 90+40-Forth the 6 and 8 they left it alone because it was in the ones place.-After that you just add your two numbers together to come up with the sum.

Right to Left addition is the basic way of adding, its what your first taught.

For subtraction there are different concepts Comparison Concept, Missing Adend Concept, and Take Away concept

-Missing addend in subtraction is just basically finding the missing number. For example: 15-___?_= 10-For this the answer would be 5, because 15-5=10 ?- 6_____= 6- For this problem the answer would be 12 because 12-6=6

With the comparison concept you are just comparing 2 objects that are the same as another person and seeing who has more then the other and by how many. The attached worksheet has great help!

The take away concept is that if you a certain amount of an object say 10 and you take away 5 of those objects how many will you have left, the answer would be 5.Y-X=B10-5=5For more problems to create on your own see worksheet take away found: http://illuminations.nctm.org/lessons/TakeAway/TakeAway-AS-TakeAway.pdf