• Given the fraction 5 out of 7, you can write it as:
[tex]\frac{5}{7}[/tex]
Where 5 is the part and 7 is the whole.
Notice that, in order to obtain 15 out of 21, you need to multiply the numerator and the denominator by 3:
[tex]=\frac{5\cdot3}{7\cdot3}=\frac{15}{21}[/tex]
• Given the fraction 30 out of 50:
[tex]\frac{30}{50}[/tex]
You need to divide the numerator and the denominator by the same number, in order to reduce it. If you divided them by 5, you get:
[tex]=\frac{30\div5}{50\div5}=\frac{6}{10}[/tex]
Hence, the answers are:
• Multiply its part and whole by:
[tex]3[/tex]
• Divide its part and whole by:
[tex]5[/tex]
