These worksheets can be used for Mental Maths as well.  I will also add separate worksheets for Mental maths. 

Unit 1 Revision, Unit 4 Tens and ones, Unit 5 Number fun

Unit 11 Time

First Internal Exam

Half Yearly exam

The following tests can be used for the regular math subject as also for mental maths practice

Useful Links

Kids Challenge Mathematics:
Generate Math Question Sets for Kids(Grade 1). Questions include simple addition, smaller/larger, ascending/descending, etc.

Download Link

To install and use the software, please make sure that you have installed the Adobe AIR runtime first. This is available as a free download here. Just click on the Download now button and install it first. Then download the application file and simply double-click / open it. It will install itself. If you have any problems running this software please contact me.