## Friday, November 21, 2008

### Math problems of the week: 5th grade Investigations vs. Singapore Math

A. From "Finding Fractions of a Whole," a 5th grade Investigations (TERC) homework sheet:

1. In a school election, 141 fifth graders voted. One-third voted for Shira and two-thirds voted for Bree.

a. How many votes did Shira get? ____

b. How many votes did Bree get? ____

2. Bob, Liz, and Eli drove from Chicago to Denver. (1,050 miles).
Bob drove 1/10 of the distance.
Liz drove 4/10 of the distance.
Eli drove 1/2 of the istance.
How many miles did each person drive?

Check to make sure the total is 1,050 miles.

a. Bob: _____ miles b. Liz: _____ miles c. Eli: _____ miles

3. Carlos and Rick paid \$8.75 for a present. Carlos paid 2/5 of the total amount and Rick paid 3/5 of the total.

a. How much did Carlos pay? _____
b. How much did Rick pay? ______

4. A pizza costs \$12.00, including tax. Scott paid 1/4 of the total cost. Trung paid 1/3 of the total cost. Pritish paid 1/6. Bill paid the rest. How much did each person pay?

a. Scott: \$____ b. Trung: \$____ c. Pritish \$_____ d. Bill: \$____

B. From 5th grade Singapore Math Primary Mathematics 5a, fractions word problems:

1. A tank is 4/5 full of water. If 40 gal more water are needed to fill the tank completely, find the capacity of the tank.

2. There are 1400 students in a school. 1/4 of the students wear eyeglasses. 2/7 of those who wear eyeglasses are boys. How many boys in the school wear eyeglasses?

3. Larry spent 1/2 of his money on a camera and another 1/8 on a radio. The camera cost \$120 more than the radio. How much money did he have at first?

4. Mrs. Ricci had \$580. She used 2/5 of it to buy an electric fan. She also bought a tea set for \$60. How much money did she have left?

-------
Extra Credit:

Which problem set involves more "inquiry," "critical thinking," and "argumentation"--all those critical 21st Century Skills we keep hearing about?

#### 1 comment:

Lsquared said...

Here, here. I've enjoyed looking at the "standards based" texts, and there's some cool things in them, but the problems just aren't very hard, except linguistically. I agree with the standards writers that we should be teaching conceptually, and with illuminating problems and contexts, but I'm very disappointed in the textbooks because while one can argue that they teach conceptually, they do it by teaching only the easy stuff, and skipping the hard parts.