Question

now use the number line to find the missing factor. 0.4 times what number is 2.0? enter your answer.
0 0.4 0.8 1.2 1.6 2.0
0.4 × ? = 2.0

Explanation:

Step1: Recall the multiplication formula

We know that in a multiplication equation \( a\times b = c \), to find \( b \) when \( a \) and \( c \) are known, we use \( b=\frac{c}{a} \). Here, \( a = 0.4 \) and \( c=2.0 \), so we need to calculate \( \frac{2.0}{0.4} \).

Step2: Analyze the number line

Looking at the number line, each step from \( 0 \) to \( 0.4 \) to \( 0.8 \) etc., is an increment of \( 0.4 \). Let's count how many times we add \( 0.4 \) to get to \( 2.0 \). Starting from \( 0 \):

• \( 0 + 0.4=0.4 \) (1 time)
• \( 0.4+0.4 = 0.8 \) (2 times)
• \( 0.8 + 0.4=1.2 \) (3 times)
• \( 1.2+0.4 = 1.6 \) (4 times)
• \( 1.6+0.4=2.0 \) (5 times)

Or using division: \( \frac{2.0}{0.4}=\frac{20}{4} = 5 \).

Answer:

\( 5 \)