## The Critical Building Block Assessment **CBA**

**1.23 + 8 = ?**

Poor foundation in place value impacts grade level math.

Goal: can student find the perimeter of a rectangle?

At an urban high school, 41% of students could not answer this question: 1.23 + 8 = ?

The most popular wrong answer was 1.31

Test writes use “age appropriate” numbers. But that leads to obscuring the result. A student may know how to calculate the perimeter of a rectangle but not know how to add decimals.

Poor foundation in multiplication of simple fractions impacts grade level math.

**Typical 10th grade question:**

**Goal:** Can student solve a probability of independent events problem?

**Example:** What is the probability of both “heads” in a coin toss and rolling an even number with a single dice?