Decimals – Subtraction, Addition, Multiplication, Division, Decimals to Fractions. These maths skills are commonly tested in 11+ exams and Selective School exams in the UK.
Examples
Example Question 1:
(a) 3.6 × 1.4 = ?
(b) 29.9 ÷ 2.3 = ?
Answers: (a) 5.04 (b) 13
Explanations:
(a) First take out the decimal points and multiply 36 × 14 = 504. Next, counting from the right to the left, put back the decimal point for the same number of places as the number of decimal digits in the sum (the decimal numbers were .6 and .4) = 2 decimal places → 5.04
(b) First multiply both the divisor (2.3) and the dividend (29.9) by 10 so that the decimal point is gone from the divisor. You are left with the sum 299 ÷ 23 = 13
Example Question 2:
(a) What is 0.8 as a fraction?
(b) What is 0.14 as a fraction?
(c) What is 1/7 as a decimal?
Answers: (a) 4/5 (b) 7/50 (c) 0.14
Explanations:
(a) The first decimal place is tenths, so 0.8 = 8/10 which is simplified to 4/5
(b) The first decimal place is tenths and the second decimal place is hundredths, so 0.14 = 14/100 which is simplified to 7/50
(c) Divide the numerator (1) by the denominator (7) to 3 decimal places and then round it to two places: 1 ÷ 7 = 0.142 which is rounded to 0.14
Video Tutorials
Subtraction – Column
Addition – Column
Multiplication
Division
Division
Decimals to Fractions – Part 1
Decimals to Fractions – Part 2
