The numbers in this sequence increase by the same amount each time. Write the missing numbers.
The question tells us that the numbers increase by the same amount each time. We don’t know what the first number in the sequence is. But we can find out how much the numbers increase by each time by finding the difference between the second and the third numbers in this sequence.
What’s the difference between 42 and 49? The number has increased by seven. 42 and seven makes 49. To find the fourth number in the sequence, we can add seven to 49, which is 56. 56 plus seven is 63. And 63 plus seven is 70.
We still need to find the first number in the sequence. We know that if we’re counting from left to right, the numbers increase by seven. So if we work backwards, the numbers must decrease by seven each time. So we can find the first number in the sequence by subtracting seven from the second number in the sequence. 42 take away seven is 35.
The missing numbers are 35, 56, and 70.