Tips for Helping your Fifth Grader with Division in Math Homework

Fifth grade math involves often-confusing concepts including multiplication and division. Although students may have been introduced to these concepts before, they are now asked to master these skills before moving on to more advanced topics like algebra and geometry in middle school.

Reverse Multiplication

Division determines how many times one value goes into another. It is the reverse of multiplication, and involves subtraction rather than addition. There are many different ways to divide and ways to check that to the answer comes out correctly. If the number ends in zero, entire number must be divisible by ten. If the last digit is even, then the number is divisible by two; if the last digit is five, the entire number can be divided by five.

Dividing by 4, 8, and 16

If the last 2 digits of a number can be divided by four, the whole number is divisible by 4. If the last three digits can be divided by eight, the whole number can be divided by eight. If the last four digits can be divided by sixteen, the whole number can be divided by sixteen.

Divding by 3 and 9

If all of the digits in a number add up to a number that is divisible by three, the whole number must be divisible by three. If the sum of the digits is divisible by 9, the whole number will be divisible by 9.

Dividing by 6 and 11

A neat trick is to add up every other digit, resulting in a new number. Then add up the leftover digits - if the answer is the same or if both answers are multiples of 11, the whole number will be divisible by eleven. You can find out is a number is divisible by six if it is also divisible by three and by two. The only single digit number that has no trick is seven.

Long Division

When long division equations involve multiple-digit numbers on both sides, these tricks may not work so well. These equations may have answers that are not whole numbers. Subtraction skills will help make finding the answers easier.

Take as an example the equation of 12 divided into 3458. You first need to see how many times 12 goes into 34. The answer is two, which makes 2 the answer's first digit. Since it only goes in twice there is a remainder of 10. The next step involves seeing how many times 12 goes into 105. This makes 8 the second digit in the answer, with 9 as the remainder. The last step involves seeing how many times 12 goes into 98. The last digit placed before the decimal is 8, but there's still a remainder of 2. The answer comes out to 288.2. It will be easier to visualize if written down.