Question

©MP.4 Model with Math

Answer 1

Answer:

The drawings are in the picture attached and the explanations are below.

Question 1.

• Equation: w = 10 × 8 lb

• Solution: x = 80 lb

Question 2:

• Equation: d = 10×8 lb - 8 lb
• Solution: d = 72 lb

Explanation:

Question 1:

• Statement 1: Mary was born, she weighet 8 lbs
• Statement 2: When she was 10 years old weighed 10 times as much

                              w = 10 × 8 lbs = 80 lbs

Explanation of the drawing:

Each cell represents 8 lbs, which was the weight when she was born. There are 10 cells, representing that the amount 8 lbs is repeated 10 times.

Then, the multiplication is represented  an abbreviated sum:

• 8 + 8 + 8 + 8 + 8 + 8 + 8 + 8 + 8 + 8 = 10 × 8 = 80

Question 2:

• Statement: find the difference, d, between Mary's weight when she was 10 years old and when she was born.​

        d         =          80 lbs   -     8 lbs   =       72 lbs

        ↑                       ↑                  ↑                  ↑

 difference       10 years old      born          solution

Explanation of the drawing:

• When you subtract one cell (8 lb) from ten cells (10 × 8 = 80 lb), you obtain nine cells ( 9 × 8 lb = 72 lb).