# The Cookie Puzzle that’s driving people crazy! Written by Isha Chakraborty

Bio

Did you know that 4th December is celebrated as the National Cookie day? As odd as the day sounds, we at the Cuemath wouldn’t leave a chance to put an interesting mathematical twist to the day. As a result of which this very interesting puzzle was formed:

Can you find out the values of the elements, namely the cookie, the cookie monster, the sugar cubes, flour bags, and the milk carton?

So what’s the solution?

The puzzle works in a grid multiplication format, meaning- you need to multiply each element on the outside of the grid to get the value inside the grid.

Let’s consider each column as Column A, B, and C.
And each row as Row 1, 2, and 3.
So to get the value of the first box, you will have to multiply the element on top of column A with the element beside Row 1.

Let’s consider column A:

Write all the equations you can form from the multiplication of the rows with column A.

We can derive from the first equation that the value of either the chocolate or the cookie is 0 (Anything multiplied by 0, will give 0 as a product). But the next two equations make it clear that it’s the chocolate that has a value of 0.

Let’s consider column B now:

Write all the equations from the multiplication of the rows with column B.

The easiest way to solve this is to start from the last equation:

Therefore, Cookie Monster = √36 = 6

Now, use the value of Cookie Monster in the second equation:

½ x Cookie Monster = Sugar Cube

I.e ½ x 6 = Sugar Cube

Therefore, Sugar Cube = 3.

Using the value of the cookie monster and Sugar Cube in the first equation you’ll get:

I.e Cookie = 12/6 = 2

Consider Column C:

Since we already know the value of the cookie monster, we’ll start solving equation 3.

Cookie Monster x Flour bag = 24

I.e  6 x Flour bag = 24

Therefore, Flour bag = 24/6 = 4

Substituting the value of flour bag into the second equation we have:

½ x Flour bag = 2 Milk Bottles

I.e ½ x 4 = 2 Milk Bottles

Therefore each milk bottle = 1

To sum it all up, the values of the elements in the grid are:

Did you get it right?

Why should your child learn multiplication using a multiplication grid?

The multiplication grid method acts as a great starting point to help your child understand and solve multiplicative problems involving multi-digit numbers. We’ve often seen, kids struggle with multi-digit multiplication, as they’re unable to break the numbers into smaller chunks.

The grid method, although different from how your child would learn multiplication, is often considered to be more reliable as children make less mistakes when using the grid.

This method of multiplication greatly emphasizes on the application of repeated addition.

For example – to multiply big numbers, like 234 with 32 your child may take a long time, or be perplexed by the size of the numbers. However, they can easily solve the same using their multiplication table knowledge of 2, 3 and 4. Here’s how:

Upon adding all the values inside the grid children are able to reach the multiplicative value of 234 x 32= 7488, just by knowing their 2,3 and 4’s tables.

The traditional method is although ultimately faster and much more compact; it requires two significantly more difficult multiplications that children may at first struggle with. Compared to the grid method, traditional long multiplication may also be more abstract and involves less clarity, so some children find it harder to remember what is to be done at each stage and why.

The grid method can also be used not just to multiply general numbers, but also to multiply fractions and decimal numbers as well.