Let's learn with some examples.
Billy has three bags of sugar. The first bag weighs 13 kilograms. The second bag weighs 9 kilograms. The third bag weighs 11 kilograms. How much do the three bags of sugar weigh in all?
Let's draw a diagram to help understand the problem.
Tip: "kg" is short for kilograms.
We need to add all three weights.
Let’s write an equation for that.
13 kg + 9 kg + 11 kg = ?
Let's use column form to find the answer:
The total is 33 kilograms.
Always write your answer as a sentence, so people know what your answer means.
The three bags of sugar weigh 33 kilograms.
Great job. 👏
John weighs 56 pounds. His older brother Harry weighs 72 pounds. How much heavier is Harry than John?
We need to figure out how much heavier Harry is than John.
It helps to draw a picture.
Tip: 'lb' is short for pounds.
What do we need to do?
You got it. We need to subtract.
Let’s write an equation for it:
72 - 56 = ?
We can write the numbers in column form.
The answer is:
Harry is 16 pounds heavier than John.
Fantastic. 🌟
There are 7 pencils in a box. Each pencil weighs 6 grams. What is the total weight of all seven pencils in the box?
We need to figure out the weight of all 7 pencils.
We can add the weights over and over until we get the answer.
But it would be faster to multiply.
This is our equation:
6 g × 7 = 42 grams
The answer is 42 grams. We write it as a sentence:
The total weight of all the seven pencils in the box is 42 grams.
Great job.
There are nine cakes in the shop. Each cake has the same weight. They weigh 135 pounds in total. How much does each cake weigh?
We know the total, but we don’t know the weight of each cake.
We need to divide the total weight by 9!
The equation for it looks like this:
135 ÷ 9 = ?
We use long division to solve this equation:
The answer is 15.
Each cake weighs 15 lb.
Wow, those are pretty big cakes.
Excellent work learning how to solve weight word problems. 🎉
Now, practice some problems on your own.