Math for Life and Food Service

1
Math for Life and Food Service

• Chapter 5 Objectives
• Fractions and Percents
• Converting
• Simple Interest
• Ratio of

2
Common Fraction Conversions
3
Converting Fractions to Percents
In mathematics, / (slash) means divided by
4
Converting Mixed Numbers to Percents
5
Convert to Percent

• 70
• 40
• 37.5
• 180
• 290

6
Common Formulas
Interest Principal x Rate x Time
7

• Three pounds of a fifteen lb turkey contains
  dark meat. What percentage of the turkey is dark
  meat?

Step 1 Define the part and the whole 3 lbs
is part of the turkey 15 lbs is the whole
turkey Step 2 Divide 3 15 0.2 Step
3 Convert decimal to percent 0.2 20 of
the turkey is dark meat.
8

• Vicky spends 300.00 of her monthly income on
  clothes. If her monthly income is 2,000.00, what
  percent of this does she spend on clothes?

Step 1 Define the part and the
whole 300 spent on clothes 2,000 monthly
income Step 2 Divide 300 2000
0.15 Step 3 Convert decimal to percent
0.15 15 of income is spent on clothes.
9

• Vicky spends 2400.00 of her monthly income on
  clothes. If her monthly income is 2,000.00, what
  percent of this does she spend on clothes?

Step 1 Define the part and the
whole 2400 spent on clothes 2,000
monthly income Step 2 Divide 2400 2000
1.2 Step 3 Convert decimal to percent
1.2 120 of income is spent on clothes.
10
Practice Problems

• Tanya eats 5 pieces of a pizza that was cut into
  eighths. What percent of the pizza did she eat?
• Seven of the students earned 100 on the math
  test. There are 25 students in the class. What
  percent did not earn 100?

• 5 8 0.625
• 6.25
• 25 7 18 18 25 72

11
Solving Problems Using Proportions
The before is
The after of
CROSS MULTIPLY DIVIDE
12
What number is 30 of 9?
9 x 30 270
270 100 2.7
13
Practice Problems

• What number is 15 of 55?
• 18 is 30 of what number?
• 25.5 is what percent of 75?

• 55 x 15 825
• 825 100 8.25
• 18 x 100 1800 1800 30 60
• 25.5 x 100 2550 2550 75 34

14
Interest Principal x Rate x Time

• Kathys interest rate is 6 for one year. How
  much simple interest will she pay on a four-year
  loan of 1275?

Step 1 Principal x Rate x Time 1275 x 6
x 4 Step 2 Convert 1275 x 6.75
x 4 1275 x 0.0675 x 4 344.25
in interest
15
Interest Principal x Rate x Time

• Harriet charged her neighbor a 7 simple
  interest on a loan of 950. How much money will
  she receive when the loan is paid in one year?

Step 1 Principal x Rate x Time 950 x
0.0725 x 1 68.875 68.88 in
interest Step 2 Add interest to the
principal 68.88 950 1,018.88 total amount
16
Practice Problems

• Ginas interest rate is 5   for one year. How
  much simple interest will she pay on a 2-year
  loan of 4,500?
• An accountant invested 2,000 at a simple
  interest rate of 9 . What total amount of
  money will she have from her investment a the end
  of the year?

• 4500 x 0.052 x 2 468 interest
• 2000 x 0.0925 x 1 185 2000 2,185 total