The worksheets are perfect for someone who teaches elementary school math or tutor's children, homeschools, or is interested in additional resources to brush up on basic math.
I think that the calculators are also extremely helpful... I am always converting between different units and different easy calculations. Its always helpful to be able to confirm your answer!
I am borrowing some of the descriptions from the website but also giving you a few thoughts of my own:
Age Calculator -
http://www.dadsworksheets.com/age-calculator.html
This age calculator allows you to enter your birthday and then it shows you each birthday for the next one hundred years. If you are asking yourself, "How many days until my birthday?" this calculator will show you that as well. If you hover over the birthday's in the left panel of the age calculator, you can see what day of the week your birthday lands on for your next birthday, future birthday days and past birthdays. The age calculator also uses your birthday to determine your western astrological sign and your Chinese astrological sign.
Note: The age calculator only works for dates within the last century
Factoring Calculator -
http://www.dadsworksheets.com/factoring-calculator.html
This factoring calculator takes as input a positive integer and uses trial division to determine all of the factors of that number. To find the factors for a number, simply enter it at the top of the calculator and it will be decomposed instantaneously.
Prime Factorization Calculator -
http://www.dadsworksheets.com/prime-factorization-calculator.html
This prime factorization calculator allows you to enter a composite number, and it produces a list of the prime numbers that, when multiplied, produce the original composite number. Use this factorization calculator to produce a factor tree, or just determine the list of primes that divide a given integer.
I really like the factor trees and wish someone would have showed me this calculator when I was learning to factor numbers! Very easy to visualize! There is also a lot of explanation of what factoring means which is super helpful!
Fraction Calculator -
http://www.dadsworksheets.com/fraction-calculator.html
This page hosts a fraction calculator that can perform addition, subtraction multiplication or division of two fractions. The values for the calculation can be simple or mixed fractions, or consist of only wholes. Input of improper fractions is allowed. Enter the values directly into the corresponding locations in the fraction calculator and the answer will be updated in real time. A visualization of the operand fractions and the answer fraction is shown in the panel underneath where the values are entered.
The explanations on this page are phenomenal... for example they relate something "painful" like fractions to real world things like "A half cup of sugar in a recipe." Who is going to complain about sugar?
Percentage Calculator -
http://www.dadsworksheets.com/percentage-calculator.html
This online percentage calculator shows how a percentage is represented as a fraction of a number. To find a percentage of a number out of a total, simply enter the values in left side of the calculator with the partial number as the numerator (the value on the top) and the total as the value on the bottom (the denominator). The calculator will calculate percentage value numerically, and show you the same value as represented visually.
This percentage calculator also functions as a percentage to fraction calculator. Simply leave the numerator and denominator values blank (or click the ‘Clear’ button) and then enter a percentage. The corresponding values will be shown in the main panel of the fraction calculator.
Countdown Timer -
http://www.dadsworksheets.com/timer.html
It’s not hard to find a countdown timer online, but if you’re looking for the best countdown timer on the Internet, then you’ve found it! This online timer is great for use as a classroom timer, cooking timer, test timer or any other type of countdown timer you can think of. The ‘Zoom’ button simplifies the timer display and makes this timer work very well on projectors or smart boards in the classroom.
This online timer will countdown a time you enter in seconds, MM:SS or HH:MM:SS format. You can choose a sound that will play when the countdown timer starts, one that plays when the countdown reaches the halfway mark, one that plays when the timer is near the end, and a final sound that plays when the countdown timer expires.
Math Worksheets -
http://www.dadsworksheets.com/worksheets.html
There are many many worksheets in a wide range of topics. Not only are there basic arithmetic (operations) worksheets, but flash cards, puzzles, and more complex topics. For example, there are several categories of fractions, word problems, pre-algebra, economics, time, and basic geometry.
You can also access graph and handwriting paper from this page.
Multiplication Chart -
http://www.dadsworksheets.com/charts/multiplication-chart.html
There are several high resolution multiplication table pages with options of 1-9 (products 1-81), 1-10 (products 1-100), 1-12 (products 1-144) and 1-15 (products 1-255). You can select black and white as well as color grids.
My favorite is the small, pocket sized ones which would be very easy to use as a bookmark or other portable guide.
Addition Worksheets -
http://www.dadsworksheets.com/worksheets/addition.html
The worksheets on this page introduce addition math facts, multiple digit addition without regrouping, regrouping, decimals and other concepts designed to foster a mastery of all things addition. All of the worksheets include answer keys, and there are four versions of each worksheet with different problems.
You can select worksheets based on topic (i.e. no carry) or design (spiral).
Subtraction Worksheets -
http://www.dadsworksheets.com/worksheets/subtraction.html
The subtraction page is similar to the addition page but has many options for borrowing (or not!) numbers. Also worksheets introduce students to negative numbers.
Multiplication Worksheets -
http://www.dadsworksheets.com/worksheets/multiplication.html
There are many different worksheets on this page... some as activity sheets and others as quizes. As you scroll down the page, you begin to see larger numbers and decimals.
Division Worksheets -
http://www.dadsworksheets.com/worksheets/division.html
The division worksheets are also fantastic! There are remainders, roots, and mixed multiplication and division worksheets.
Long Division Worksheets -
http://www.dadsworksheets.com/worksheets/long-division.html
The long division worksheets in this section of the site are designed to introduce various topics gradually, so that long division skills are built incrementally and areas of difficulty can be reinforced without creating a dread of long division problems. Learning how to do long division brings in to play many steps, including multiplication and subtraction as well as basic understanding of the division facts. As long as students begin with a strong mastery of the prior math operations, long division can be an opportunity to show off their results of their hard work on previous parts of their mathematical journey.
Topics include multi digit divisors and decimal quotients in addition to division by factors of 10 and 25.