How to Solve Decimal Word Problems

We deal with decimals in real life all the time.

      Decimals are numbers with whole numbers and fractions together.

When we count money, we deal with decimals! 😺

Let's try to solve a real world problem with decimals.

Sam had saved $12.50. He just earned $9.75 for babysitting. How much money does Sam have now?

👉 We need to add the amounts together.

The model, or drawing, would look like this:

👉 Now, write an equation and solve it.

$12.50 + $9.75 = $22.25

👉 Finally, write your answer as a sentence.

Sam now has $22.25.

Make sure to add the dollar sign before the number.

Water in a Pail Example

A pail had 2.25 liters of water in it. Then Ken took 1.55 liters of water from it. How much water is left in the pail?

How do we solve this problem? 🤔

👉 We need to subtract.

Our model for this problem looks like this:

2.25L is the whole, and 1.55L is the part that we subtract from it.

You can also draw it as a whole-part diagram:

Now, we write an equation.

2.25 L - 1.55 L = 0.7 L

Finally, we write a complete sentence.

0.7 liters (or 0.7 L) are left in the pail. ✅

The Oak Tree and Maple Tree Example

The oak tree is 65.7 ft tall. The maple tree is 20.9 ft shorter than the oak tree. How tall is the maple tree?

👉 Let's gather clues first.

Important words and numbers have been circled.

👉 Then, we draw a model.

We need to subtract the difference between the height of the 2 trees from the height of the maple tree.

👉 Now, we write the equation.

65.7 ft - 20.9 ft = 44.8 ft

👉 Lastly, we write our answer in a complete sentence.

The maple tree is 44.8 ft tall. ✅

Great work! 

Now, complete the practice. 😺 

Practice tip: it will help to have a pencil and paper to do your scratch work!