Together with the 1-12 x multiplication and division facts, and their basic addition facts, children should be able to answer the following Year 6 mental maths questions:

• Addition and subtraction of multiples of 10 (e.g. 70 + 30= 100, 50 + 60 = 110, 20 + 40 = 60);
• Addition and subtraction of multiples of 100 (e.g. 300 + 400 = 700, 400 + 600 = 1,000, 800 + 500 = 1,300);
• Addition and subtraction of multiples of 1000 (e.g. 3000 + 4000 = 7000);
• Double and halves of multiples of 10 to 100 (e.g. double 60 = 120, half 50 = 25);
• Quadruples (x4) of all numbers to 10 (e.g. 6 x 4 = 24);
• Multiplying two-digit number by 10 (e.g. 24 x 10 = 240);
• Halves of any number up to 100 (e.g. half of 22 = 11, half of 51 = 25.5);
• Multiplying and dividing any number by 10 and 100 (e.g. 24 x 100 = 2,400, 45 ÷ 100 = 0.45, 3.4 x 10 = 34);
• Multiplication of multiples of 10 and 100 based on known facts (e.g. 40 x 40 = 1,600);
• Squares of all number up to 12;
• And cubes of 2,3,4 and 5.

Please follow the link below for further information. 

https://thirdspacelearning.com/blog/mental-maths-strategies/#15-mental-maths-year-6-