Division
Division means to break apart into pieces. It is often done when objects need to be broken up into groups of the same size.
Division Vocabulary:
Dividend: the number being divided
Divisor: the number the dividend is being divided by
Quotient: the answer to a division problem
Remainder: the number left after all whole numbers have been divided
Divisor: the number the dividend is being divided by
Quotient: the answer to a division problem
Remainder: the number left after all whole numbers have been divided
Estimating: Rounding/Compatible Numbers
Sometimes rather than finding an exact answer, one can use compatible numbers or rounded numbers to get an estimate of the answer to a division problem. This is a good way to find an answer without dealing with remainders, and allows the student to determine whether an exact answer, once found, is reasonable based upon an estimate.
Are all division answers reasonable?
Sometimes the exact answers to a division problem are not reasonable answers because they don't answer the question being asked or they are not realistic.
Example: 8 kids can sit at each table in the cafeteria and 50 kids eat lunch together. How many tables are needed for all 50 kids to have a seat? The exact answer would be 50 divided by 8 = 6R2 (or 6 with a remainder of 2). However, what does this mean about the amount of tables? Can there only be part of a table? - No! There's either a table or no table. If we say just 6 tables are needed, that means 2 kids can't sit to eat their lunch. So we have to say that 7 tables are needed so that all 50 kids can sit and eat.
Students need to think very carefully about what the question is asking them to find and then answer that question with an answer that makes sense - not always the exact answer.
Example: 8 kids can sit at each table in the cafeteria and 50 kids eat lunch together. How many tables are needed for all 50 kids to have a seat? The exact answer would be 50 divided by 8 = 6R2 (or 6 with a remainder of 2). However, what does this mean about the amount of tables? Can there only be part of a table? - No! There's either a table or no table. If we say just 6 tables are needed, that means 2 kids can't sit to eat their lunch. So we have to say that 7 tables are needed so that all 50 kids can sit and eat.
Students need to think very carefully about what the question is asking them to find and then answer that question with an answer that makes sense - not always the exact answer.
Rules of Divisibility:
by 2: if the number ends in an even number, 2,4,6,8....
by 3: if the addition of the number is a multiple of 3
by 4: if the last two numbers are divisible by 4( zero is an exception)
by 5: if the number ends in 0 or 5
by 6: if the number is divisible by 2 and 3
by 9: if the addition of the number is a multiple of 9
by 10: if the number ends in 0.
by 3: if the addition of the number is a multiple of 3
by 4: if the last two numbers are divisible by 4( zero is an exception)
by 5: if the number ends in 0 or 5
by 6: if the number is divisible by 2 and 3
by 9: if the addition of the number is a multiple of 9
by 10: if the number ends in 0.
