Transum Software

Decimal Plus

Practise mental and written methods for adding and subtracting decimal numbers.

Level 1 Level 2 Level 3 Description Help More Decimals

This is level 1; Adding and subtracting numbers less than ten with one decimal place. You can earn a trophy if you get at least 9 correct and you do this activity online.

3.1 + 1.1

Correct Wrong

3.2 − 2.3

Correct Wrong

2.2 + 3.2

Correct Wrong

3.5 − 3.4

Correct Wrong

3.4 + 4.3

Correct Wrong

5.5 − 2.5

Correct Wrong

5.6 + 4.6

Correct Wrong

3.5 − 1.5

Correct Wrong

6.6 + 7.5

Correct Wrong

6.7 − 2.6

Correct Wrong

6.6 + 7.8

Correct Wrong

8.8 − 7.8

Correct Wrong


This is Decimal Plus level 1. You can also try:
Level 2 Level 3

There is also an exercise on multiplication and division of decimals called Decimal Times.


Try your best to answer the questions above. Type your answers into the boxes provided leaving no spaces. As you work through the exercise regularly click the "check" button. If you have any wrong answers, do your best to do corrections but if there is anything you don't understand, please ask your teacher for help.

When you have got all of the questions correct you may want to print out this page and paste it into your exercise book. If you keep your work in an ePortfolio you could take a screen shot of your answers and paste that into your Maths file.

This web site contains over a thousand free mathematical activities for teachers and pupils. Click here to go to the main page which links to all of the resources available.

Please contact me if you have any suggestions or questions.

Email address

Mathematicians are not the people who find Maths easy; they are the people who enjoy how mystifying, puzzling and hard it is. Are you a mathematician?

Comment recorded on the 11 January 'Starter of the Day' page by S Johnson, The King John School:

"We recently had an afternoon on accelerated learning.This linked really well and prompted a discussion about learning styles and short term memory."

Comment recorded on the 21 October 'Starter of the Day' page by Mr Trainor And His P7 Class(All Girls), Mercy Primary School, Belfast:

"My Primary 7 class in Mercy Primary school, Belfast, look forward to your mental maths starters every morning. The variety of material is interesting and exciting and always engages the teacher and pupils. Keep them coming please."

Featured Activity



Answer multiple choice questions about basic mathematical ideas. If you get a number of questions correct you will be invited to post a question of your own. The bank of questions grows larger every day.


There are answers to this exercise but they are available in this space to teachers, tutors and parents who have logged in to their Transum subscription on this computer.

A Transum subscription unlocks the answers to the online exercises, quizzes and puzzles. It also provides the teacher with access to quality external links on each of the Transum Topic pages and the facility to add to the collection themselves.

Subscribers can manage class lists, lesson plans and assessment data in the Class Admin application and have access to reports of the Transum Trophies earned by class members.

If you would like to enjoy ad-free access to the thousands of Transum resources, receive our monthly newsletter, unlock the printable worksheets and see our Maths Lesson Finishers then sign up for a subscription now:


Go Maths

Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths page is an alphabetical list of free activities designed for students in Secondary/High school.

Maths Map

Are you looking for something specific? An exercise to supplement the topic you are studying at school at the moment perhaps. Navigate using our Maths Map to find exercises, puzzles and Maths lesson starters grouped by topic.


If you found this activity useful don't forget to record it in your scheme of work or learning management system. The short URL, ready to be copied and pasted, is as follows:

Do you have any comments? It is always useful to receive feedback and helps make this free resource even more useful for those learning Mathematics anywhere in the world. Click here to enter your comments.


©1997-2019 WWW.TRANSUM.ORG

© Transum Mathematics :: This activity can be found online at:

Description of Levels



Level 1 - Adding and subtracting numbers less than ten with one decimal place

Level 2 - Adding and subtracting a wide range of decimal numbers

Level 3 - Real life problems involving the addition and subtraction of decimal numbers

There is also an exercise on multiplication and division of decimals called Decimal Times.

Adding and Subtracting Decimals

This video will teach you how to perform the basic operations with decimals.

Don't wait until you have finished the exercise before you click on the 'Check' button. Click it often as you work through the questions to see if you are answering them correctly.