4th Grade Math Topic 12 Adding and Subtracting MAFS.4NF.2.3, NF 1.1, NF 1.2

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Terms in this set (...)

Common Denominator
1. A number that can be divided by each of the denominators of a group of fractions.
2. A number that is a multiple for each denominator in a group of fractions.
¾ and ¼ have a common denominator of 4!
Equivalent
1. Having the same value, use, or meaning.
2. Equal but not 'supposable'.

Examples: The area of the square and triangle are equivalent! ½ and 3/6 are equivalent fractions.
Benchmark
Fractions
Fractions that are commonly used for estimation and can be recognized easily.
¼, 1/3, ½, 2/3, and ¾.
Denominator
• The number below the
fraction bar in a fraction;
the number of equal
parts in all.
• The number of equal parts that make up the whole!
Improper Fraction
A fraction in which the numerator is greater than or equal to the denominator.
Mixed Number
A number that has a whole number and a fraction
Simplest Form
A fraction is in simplest form when the numerator and denominator cannot be any smaller. Example: 6/8 can be simplified to ¾. 5/10 can be simplified to ½.
To simplify a fraction, divide the top and bottom by the highest number that can divide into both numbers exactly!
Equation
An equation has expressions that contain one or more variable. To solve it, you need to find out the value of the variable to make the equation balanced or equal on both sides.
Example: 3/10 + 5/10 = 8/10
Reasonableness
Your answer looks like it fits the problem, such as when you use estimation or verify the answer by doing it another way.
180 is a reasonable answer for 36 X 5 because 30 X 5 = 150 and 6 X 5 = 30. Then, 30 + 150 = 180.
3000 is not a reasonable answer for 20 X 15. It is too high because 10 X 20 = 200 and you only have 5 more groups of 20 (5X 20 = 100) left. That would make 300.