Adding and Subtracting Fractions: math test solutions, Grade 4 – download the PDF

1 Like denominators / 4 pts

a) \(\dfrac{8}{11}\) (1 pt)

b) \(\dfrac{6}{15}\) (1 pt)

c) \(\dfrac{7}{7}=1\) (1 pt)

d) \(\dfrac{9}{9}-\dfrac{2}{9}=\dfrac{7}{9}\) (1 pt)

2 Converting / 3 pts

a) \(17\div5=3\) r 2, so \(3\dfrac{2}{5}\). (1 pt)

b) \(4\times8+3=35\), so \(\dfrac{35}{8}\). (1 pt)

c) \(23\div6=3\) r 5, so \(3\dfrac{5}{6}\). (1 pt)

3 Mixed numbers / 4 pts

a) \(4\dfrac{7}{9}\) (1 pt)

b) Wholes 5, fractions \(\dfrac{13}{10}=1\dfrac{3}{10}\), total \(6\dfrac{3}{10}\). (1 pt)

c) \(4\dfrac{3}{8}\) (1 pt)

d) Regroup \(6\dfrac{1}{5}=5\dfrac{6}{5}\), then \(5\dfrac{6}{5}-2\dfrac{4}{5}=3\dfrac{2}{5}\). (1 pt)

4 Decomposing / 3 pts

a) \(\dfrac{9}{10}\) is nine copies of \(\dfrac{1}{10}\): \(\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}+\dfrac{1}{10}\). (1 pt)

b) For example \(\dfrac{4}{10}+\dfrac{5}{10}\) and \(\dfrac{2}{10}+\dfrac{7}{10}\). (1 pt)

c) \(3\dfrac{1}{4}=\dfrac{13}{4}=13\times\dfrac{1}{4}\). (1 pt)

5 Multiplying / 3 pts

a) \(\dfrac{12}{7}=1\dfrac{5}{7}\) (1 pt)

b) \(\dfrac{30}{8}=3\dfrac{6}{8}\) (1 pt)

c) \(\dfrac{12}{4}=3\) (1 pt)

6 Fruit stand / 3 pts

a) Wholes \(3+2=5\), fractions \(\dfrac{3}{4}+\dfrac{2}{4}=\dfrac{5}{4}=1\dfrac{1}{4}\). Total \(6\dfrac{1}{4}\) pounds. (1.5 pts)

b) \(6\dfrac{1}{4}-1\dfrac{3}{4}=5\dfrac{5}{4}-1\dfrac{3}{4}=4\dfrac{2}{4}\). She has \(4\dfrac{2}{4}\) pounds left. (1.5 pts)