90 likes | 272 Views
Subtracting Integers. 7 th Pre-Algebra. Warm up. 1. A person blinks an average of 25 times per minute when awake. Last year (not a leap year), Katelyn averaged 9 hours, 45 minutes of sleep each day. How many times did Katelyn blink last year?. Check HW. Subtracting Integers.
E N D
Subtracting Integers 7th Pre-Algebra
Warm up 1. A person blinks an average of 25 times per minute when awake. Last year (not a leap year), Katelyn averaged 9 hours, 45 minutes of sleep each day. How many times did Katelyn blink last year?
Subtracting Integers Using number chips: A. 5 – 3 = B. -5 – (-3) = C. -10 – (-5) = D. 5 – (-3) = E. 7 – (-4) = F. 4 – 9 =
Subtracting continued: Using the number line: A. 5 – 3 = B. -5 – (-3) = C. -10 – (-5) = D. 5 – (-3) = E. 7 – (-4) = F. 4 – 9 =
Real world Example The Spartan Bike Shop keeps a record of their business transactions. They start their account a zero dollars. Payments represent negative transactions. Sales represent positive transactions. Write a number sentence to represent each transaction. Then find the new balance.
Spartan Bike shop • Rent payment for shop: $1,800 • Payment for 20 new bicycles: $2,150 • Payment on office equipment: $675 • Business insurance for 6 months: $2,300 • Sale of 3 bicycles: $665 • Sale of two helmets and one baby seat: $95 • Web site advertising down payment: $250 • Sale of 6 bicycles: $1,150 • Refund to an unhappy customer: $225 • Sale of 2 bicycles, two helmets, and two air pumps: $750 • Check from manufacturer for 5 bicycles returned: $530
HW • Textbook p. 66 (9-16)