Chapter Two Lesson Two

An adult zoo elephant eats about 87 pounds of hay each day. A zookeeper needs to feed 4 elephants for 28 days in February. The zookeeper has 12,000 pounds of hay. Is this enough for the month? 87 x 28 x 4 =

Our lesson today is about Estimating Products 87 x 28 x 4 = This is an example of overestimation. When you only round factors to larger numbers, you get an OVERESTIMATE. An UNDERESTIMATE is when you only round factors to smaller numbers. 90 x 30 x 5 = 90 x 30 x 4 = 80 x 20 x 4 = 80 x 25 x 4 = 13,500 10, x 30 x 4 =12,000 6,400 8,000 Our estimated answer could be between 6,400 and 13,500 pounds of hay.

87 x 28 x 4 = 9,744 Decide whether you think an overestimate or underestimate is necessary. The time it will take to drive to your destination overestimate The number of miles you can drive on a tank of gas underestimate How much a trip will cost How much will fit in a suitcase overestimate underestimate

53 x 4 x 28 When you estimate this product, think of your overestimates and underestimates. Your estimate should be somewhere between these two. 60 x 4 x 30 = 7, x 4 x 20 =4,000 Overestimate Underestimate Your estimate = 6,000 Check – this is an accurate estimate

33 x 58 x 3 = 40 x 60 x 3 = 7,200 Overestimate Underestimate 30 x 50 x 3 = 4,500 Your estimate = 5,400

Estimation Practice 18 x 19 x 50 = 20, x 14 x 3 = 3, x 9 x 21 =9,000 4 x 79 x 24 =8,000