Multiplication up to Three Digits using the Grid Method

What is Mr. Squeaks doing with all of that stuff? Oh, Imani needs it to fuel the time machine so they can travel to the Stone Age! Before he gives them to Imani, he needs to calculate how many stones, clocks and shoes he has. In order to do that, we will practise multiplication up to three-digits using the grid method. The grid method involves drawing a rectangular model to helps us find the product of two numbers. Mr. Squeaks has five boxes with thirty-eight clocks in each. Let's help Mr. Squeaks calculate by multiplying thirty-eight times five. The first step is to set up our grid. Start by drawing a rectangle. Next, split it into the number of parts based on how many place values are in each number. Thirty eight has two place values, tens and ones, so we split our rectangle into two parts. Five has one place value so we don't break the rectangle into any more parts. Next, label each part by writing the factors in expanded form. The value of the three in the tens place is thirty and the value of the eight in the ones place is eight so we label the top thirty plus eight. Then, we label the five on the left side. The second step is to multiply each corresponding pair to find the partial products. Partial products are the answers we get when each pair of factors is multiplied. In the box on the left, we multiply five times thirty. Remember, you can ignore the zeros at first to get fifteen and then annex one zero to your answer. Five times thirty equals one hundred and fifty. Now we multiply five times eight in the box on the right, which equals forty. After we find all of the partial products, the third step is to add them. This will give us the answer to our multiplication problem. One hundred and fifty plus forty is one hundred and ninety so they have one hundred and ninety clocks. Mr. Squeaks has eight boxes with seventy-six shoes in each. We need to find the product of seventy-six times eight. First, let's set up our area model by drawing a rectangle, breaking it into parts and labelling it. When we label using expanded form, we have seventy plus six on the top and eight on the left. The second step is to multiply each corresponding pair to find the partial products. Let's find the partial product for the box on the left. What is eight times seventy? Eight times seventy equals five hundred and sixty. Now let's find the partial product for the box on the right. Eight times six equals forty-eight. Last, what is the sum of the partial products? Five hundred and sixty plus forty-eight equals six hundred and eight. That means Mr. Squeaks has six hundred and eight shoes for the time machine. Finally, Mr. Squeaks has three boxes with two hundred and forty-five stones in each. We need to find the product of two hundred and forty-five times three. The first step is to set up our grid but how does this look with a three-digit number? We still label it using expanded form, but now the model is broken into three parts since we are calculating a three-digit number. How do we label it? The top is labelled using the expanded form two hundred plus forty plus five and the three goes on the left. The second step is to multiply to find the partial products. This time, try multiplying on your own. The partial products are six hundred, one hundred and twenty and fifteen. Now, what do we do with the partial products? The last step is to find the sum of the partial products. The sum of the partial products is seven hundred and thirty-five which is the number of stones Mr. Squeaks has for the time machine. Remember, when we solve a multiplication problem using the grid method, the first step is to set up the grid. The second step is to multiply each corresponding pair to find the partial products. The third step is to find the sum of the partial products. Let's see if the time machine has enough fuel. It looks like it's working...