The idea in brief. A decimal IS a fraction whose denominator is 10, 100 or 1000. So to turn a fraction into a decimal, change its denominator into one of those and read the digits off; and to turn a decimal into a fraction, name it as that many tenths, hundredths or thousandths and then simplify. The digits of the fraction are never the digits of the decimal.
Lesson video, with the working
Decimals and fractions
2 min 37 s
The film teaches 2 questions in turn. Each question shows first; its working is written as the film explains it.
To express seven twenty-fifths as a decimal, change the denominator to 100. 25 times 4 is 100.
Multiply the numerator by 4 too. 7 times 4 is 28, so the fraction is 28 hundredths, or 0.28.
To express 0.06 as a fraction, use the place of the last digit: 6 hundredths means six over one hundred.
Divide both numerator and denominator by 2. Six over one hundred simplifies to three fiftieths.
Check for any further common factor. 3 and 50 have no common factor greater than 1.
Write the decimal as a fraction with denominator ten, one hundred or one thousand. Then simplify the fraction by dividing both terms by the same number.
Practice questions with worked solutions
Question 1 is free to try. The other 6 open in the free trial, each with its full working.
Question 1 of 7 · Intermediate · free to try(a) Express 0.44 as a fraction in its simplest form. (b) Express 1 3/5 as a…(a) Express 0.44 as a fraction…
(a) Express 0.44 as a fraction in its simplest form. (b) Express 1 3/5 as a decimal.
How can my child change between fractions and decimals in P4?
Your child learns that fractions and decimals can name the same amount.
What your child learns here
Your child learns that fractions and decimals can name the same amount. The MOE P4 outcomes include expressing decimals as fractions and expressing fractions as decimals when the denominator is a factor of 10 or 100. Place value supplies the link, while equivalent fractions help your child rewrite the amount without changing it.
Read a decimal part as tenths, hundredths or thousandths, then write it as a fraction with the matching denominator.
Simplify a fraction by dividing its numerator and denominator by a common factor, keeping the value equal to the starting decimal.
Change a fraction's denominator to 10 or 100 when the original denominator is a factor of one of those numbers, multiplying both parts equally.
Convert the fractional part of a mixed number while keeping the whole-number part, then combine the two parts in decimal notation.
Use familiar benchmarks such as one half and one whole to judge the size of a converted value before accepting the written answer.
Does the answer make sense?
Three quarters is greater than one half and less than one whole, so its decimal must lie between 0.5 and 1. Rewriting it as seventy-five hundredths gives 0.75, which fits those bounds and names exactly the same fraction.
How to practise these questions
This set contains Intermediate and Challenge questions. Intermediate items move between decimals, fractions and mixed numbers, include thousandths, and ask for a missing denominator in an equivalent fraction. One also converts an eighths fraction into a decimal. The Challenge questions combine conversion with digit restrictions: one asks for possible decimals whose simplified fractional part has a specified denominator, while another investigates fractions with denominator forty. Ask your child to separate whole-number and fractional parts before converting, then check that the two forms name the same amount. For questions asking for all possibilities, record candidates systematically and test the digit restrictions as well as the fraction's value.
Questions parents ask
Does Primary 4 require every fraction to be changed into a decimal? No. For the fraction-to-decimal direction, the P4 syllabus specifies denominators that are factors of 10 or 100. This allows your child to use equivalent fractions in tenths or hundredths. This set also includes conversions from eighths and fortieths into decimals, which extend beyond that stated denominator limit.
Why must both parts of a fraction change together? Multiplying the numerator and denominator by the same number preserves the fraction's value. Changing only the denominator changes the size of each part without adjusting how many parts are counted. Ask your child to explain the equal multiplication before reading the new fraction as a decimal.
How should my child handle a decimal greater than one? Separate the whole-number part from the decimal part first. The whole-number amount stays unchanged while the tenths, hundredths or thousandths become a fraction. Your child can then simplify that fraction and check whether the question asks for a mixed number or another equivalent form.
