Video Transcript
There are lots of ways to make
eight. What is the missing
expression? Zero plus eight. One plus seven. Two plus six. What plus what. Four plus four. Five plus three. Six plus two. Seven plus one. And eight plus zero.
There are nine ways to make
eight, but one of the expressions is missing. We could use the cube train to
help us find the missing expression. We could also find the missing
expression by working out the strategy that’s been used. If we look carefully at the
pairs of numbers or the number bonds, we can spot some patterns.
If we write down the number of
red bricks and blue bricks we’ve used to make eight, that will help us to spot
the pattern. What’s happening to the number
of red bricks? Zero, one, two, three, four,
five, six, seven, eight. The number of red bricks is
going up by one each time. We’re counting in ones. Now we found the first missing
number. Zero, one, two, three.
What’s happening to the number
of blue bricks? Eight, seven, six. The missing number is five. Eight, seven, six, five, four,
three, two, one, zero. The number of blue bricks is
getting smaller each time; it’s decreasing. We’re counting back in ones,
eight, seven, six, five. The missing expression is three
plus five. Zero and eight make five, one
and seven, two and six, and three and five. So do four plus four, five plus
three, six plus two, seven plus one, and eight plus zero.
We found all the ways to make
eight using our model and a strategy. We wrote the number bonds down
and looked for the pattern. This helped us to find the
missing addition expression. Three plus five makes
eight.
