A fifth and a tenth
Split a whole into 5 and into 10 equal parts, compare 15 and 110, and find a fifth and a tenth of an amount.
- Russia: grade 3
Guide
Russian schools teach the fifth and the tenth in Grade 3, with the half, the third and the quarter: comparing fractions and finding a part of an amount. A fraction names one of several equal parts of a whole.
If a whole is split into 5 equal parts, one part is a fifth, 15. If it is split into 10 equal parts, one part is a tenth, 110. The more parts a whole is split into, the smaller each part is: 15 is bigger than 110.
To find a fifth of an amount, divide it by 5: a fifth of 20 cm is 20 : 5 = 4 cm. A tenth of 100 roubles is 100 : 10 = 10 roubles. The child shades the parts on a bar, compares them and finds a part of an amount.